Clonerunner issues found:
Previous owner used steel shim head gaskets,(no copper coat or anything) was not religious about using coolant and apparently did not retorque many a year ago (10) when motor was built.(some headbolts felt like 30 lbs or so)Pistons look nice, especially the two that were sucking water regularly.Flat tops w/valve reliefs.no P/N yet.
Heads look OK, valves etc, still shows crosshatch in cylinder walls,but it has CAM-ITIS!
One lobe shows tell tale discoloration and graininess.Not 100% sure, but is purple and supposed to bee 284/.484.Loved it!
Comp has XE 274H-10 split pattern (230/236@.050) adv.274/286-.488/.491 110' lobe separation
and I can get amazon free freight, and I think a 25.00 rebate.
Would this be pretty close to, or better for my setup? (383 .030 906s,approx 3000 stall,3.55s,# 3800,eddy rpm intake/850 DP 3" exh w/x pipe)
It ran very strong w/the purple.No complaints, so I almost wanted the same cam, but maybe the split pattern would work better for me?
Thoughts?
Bear

It will be quite a bit milder from an idle standpoint because of the shorter durations.

The 274 is a decent cam and would likely work well.

Would be that noticeable, huh?The specs look sort of close,but I was looking at updating to a more modern grind, maybe pick up a broader power band from the split pattern.IIRC the 'purples' were not?
C

Depends on the combo whether a split pattern really will make more of anything you want. I would skip the comp cam and simply call Bullet cams and get a great grind to replace the MP piece. It's just too easy and you'll be happy with the result. Ask for Tim.

Something with similar duration will or a tad shorter will idle better and have more low end.850 is overkill for that 383 IMO.

Comp does make 'updated' versions of the purple shaft grinds, I run their 509. It is 248/254, .509". The 284 grind is like 240/246 if I recall, .484".

It will idle a bit rougher than the old MP grind, may or may not run stronger. I think possibly not, I read somewhere that with good heads and exhaust there may not be benefit from split grind.

The XE284 grind may work if you have the PV clearance.

Decisions, decisions...
Thanks all, food for thought.Maybe not so simple as a "magic" updated grind will make the sun come out, I'll lose 20 lbs, and the angels will sing.
As for the 850 carb,it was a really clean 4 corner I had that was gathering dust,ran a boatload better than the Mighty D it replaced, and Hot Rod used the same carb for their infamous 383 intake shootout IIRC.Plus I didn't have anything else good at the time.
More to follow, heads are off, time to buy a cam.
Thanks, C

A better Comp cam all around is the XE275HL. It has real Chrysler lobes, the 274 is a Chevy lobe cam. It will surprise you. If you liked the 484 cam the 275 will be better.
R.

My thought also about the .525 lift...traditional wisdom (IIRC) was with a stock 906 head, .500 lift was about it.You could go bigger,but the heads only flow so much in stock form anyway, at least up to that magic #.However,I do like the sound of the testimonial.
Are there less "radical" grinds on a chrysler lobe that are under .500?
This thing had steel shim gaskets,would be .020 compressed, so a 'regular'fel-pro is like .038 compressed, so right there is another "bonus" .018 PV clearance.I have never done the clay the piston deal, ever.Theoretically, if I re-install the purple 284/484 (or equivalent) there should be no clearance issues.If I go bigger, I'm sort of in uncharted territory.This motor had stamped steel rockers also, I am anticipating needing adj. rockers and correct length pushrods, as they will need to be "longer" by .018 with the comp. head gaskets.Yes????

The comp 274 is nothing similar to a 284/484. If you have a good set of headers, I would not worry about a split pattern.
You are going to lose a lot of top end with the 274 compared to the 284. But it would be a good cam choice imo.
It's not going to make more power though if that is what you are looking for.

Also what is your compression ratio?

As far as higher lift than the heads flow, it will still hold the valve open at or above .500 for a longer time, therefore you still gain power. If you catch my drift.

The more modern cam, XE275HL, will probably have more duration at 0.200 lift than the .484. I think you'll see an increase in max horsepower.

As far as rockers go, pick the cam, (mine is best), install it, see if preload is OK. If not, get a set of pushrods the right length. I bet your existing valvegear except for springs will be OK.

The only problem with higher lift is you need springs and retainer-to-guide clearance for it. Piston-to-valve clearance is something to check, but most bigblock Mopars have the pistons down so far that it is a non-issue.
And if you replace a steel shim head gasket with a composition gasket to increase P/V clearance, you deserve whatever loss of performance you get.
R.

Good information, good thoughts, dogdays, viperblue.
Looking at a set of used ductiles, as I am not a gambling man, and these rockers had 'acceptable' preload as far as I can tell,reasonably sure that'll go away.
The pistons do not appear to be KBs,no part number visible,pretty good wedge shaped clearance notch running across them, slightly deeper for the intake valve.Will be checking how far down in the hole they sit,just on GP.
As far as replacing a steel shim gasket with a composition and "deserving" the power loss I get,
sorry, my love affair with 60's technology only goes so far.
Not doing this for the P/V clearance, I am doing this 'cause they FAILED.(whether mis installed, not retorqued, whatever)
Sealing technology has advanced light years since they built these motors.Ditto for cam technology, hence the look at newer grinds.
No steel shims, thanks. Not worth the what is it, .2 potential compression point gain? With what passes for gasoline these days, it is not even a question anymore for me.Got a leftover set of custom detroits from Dan D I'll probably use.
Still deciding if I want to use the 440 source heads I have,too.
Thanks for all the input!Onwards!

The aluminum heads, would really wake it up. 40+ cfm more flow than stock and almost 10cc smaller chamber, will raise your compression almost a point over what you have.
A high lift cam should be fine with your pistons. I would go ahead with the high lift 275 version.

Unfortunately,these are the 1st gen "take your chances" heads.May go ahead anyway, what am I going to save them for?Good opportunity,Will run them by my friendly machine shop to check for the legendary tight guide and general valve job re-check issues.
Interestingly enough, the fellow at 44o source highly recommended the very 274 grind we are discussing for his gen 1 heads with my application.(I didn't even tell him what I was thinking, he popped up with that recommendation.).The Comp cam tech line guy Chris, stated unequivocably (whew, 10$ word) that they use chrysler blanks for chrysler cams, and he wishes the forums would let that one die???
He also likes the 274.Still thinking.

With the comp xe 274 you could run stock stamped rockers. The 275 would negate aftermarket, plus stiffer springs. With the 274, you could use what came on the source heads. Just go for it man.
Let us know how it turns out.

Comp, Comp. Comp, that's all this board ever talks about. What is it about them, and what wrong with Hughes/Engel cams That are made to take advantage of Chrysler .904 lifters? http://www.hughesengines.com/Index/produ...mp;partid=21852
http://www.hughesengines.com/Index/produ...mp;partid=21852
http://www.hughesengines.com/Index/produ...mp;partid=11429

Engle hasn't cut a hughes cam in a long time from what I've known.

Plenty of companies make cams that try to maximize use of the .904 lifter. Not just hughes. Outside the overpriced nature of most hughes cams, have at it.

1. I don't care for the original COMP Xtreme hydraulic cams:
- fast acceleration/deceleration ramps that cause a lot of valve train noise
- those same ramps also result in the valve train not RPM-ing as well as smoother lobe profiles; I've seen more than one dyno of those cams that show premature valve train "crash" compared to other profiles

2. I don't know if Comp resolved those issues w/ their HL Xtreme Chrysler lobes or not.

3. If I ever ran another hydraulic cam, I'd look for something less aggressive that would result in a "happier" valve train.

4. Hughes hasn't had Engle grind their hydraulic or solid flat-tappet cams for years, although I'm not sure who their grind of choice is now.

Thanks to whoever posted the rebuttal to Comp's in(s)ane claim, clearly a tech rep who doesn't know his stuff!

Nothing wrong with Hughes, IIRC their latest (meaning the HEH) ultra-agressive lobes are even faster than Comp's HL lobes. For example, Hughes HEH 228 lobe has 0.524 lift, while the Comp XE275HL uses 231 degrees to get 0.525" lift.If you use Hughes cams, IMHO you MUST use their spring package. There's little margin for error. Of course, pushing the edge of the envelope is what makes more power. No free lunch in the High Perf world!

My recommendation of the XE275HL cam was based on the OP's claim to like the 484 cam. If I was picking a cam without hearing that, I'd pick a significantly smaller cam. A 383 is really easy to overcam, and a 484 is at least 4 steps too big for a street type 383. A few years ago Dwayne Porter said that Comp had designed some smaller "HL" lobes, but you had to ask for them.
Usually, better heads will require less cam to make the same power. So if the OP is going to use Stealths, then the game changes.

Hughes HEH2328BL will really rock in that combination.

R.

Yes, that all may be true, however it really is all in the eye of the beholder.The car pulled like a freight train even after the 4.10 detroit got swapped for a 3.55.I liked how it ran, I liked how it sounded.I am not wanting to re-invent the wheel at this time.
Is there a lot better stuff out there? YES!
Do I want to buy it all right now? NO!
I am all for information sharing, that's why I come here.I also call various tech reps, consult my best friend the Master machinist (aerospace but built many motors), and balance it against my experiences, past and current.
Ken at Hughes could not offer me a "comparable" cam without a serious lift increase.All the decent grinds are over .500 lift.IIRC he said he'd have to go all the way back to a grind like dogdays mentioned to get what I was looking for.
As the stealths are 'on the table', if 440 source is recommending THIS VERY GRIND (274)to a lot of their customers, someone should call them and tell them they are wrong on this.
The Comp rep now, well they are there to sell cams.Their stuff is OK.
He did not insist I had to have their springs, and politely told me what they wanted for poundage, seat and open.He did not care much for anything past .500 given what I actually DO know about this motor,(not much, really).
My last two RBs (446 and 500 mega)had custom solids ground by Lunati for specific engine/chassis.I can and will do that when I can.
This goes back to the days of my T/A 340 block.
I'm sure the mild 280 crower was a good grind, but it didn't have the sound, and it didn't pull real strong mid and top end.
Swapped in the crane blazer, and it was a whole different car,picked up that heavy '70 chall like it was made of paper.And it sounded GREAT!
Gotta go with the best decision you can make given the information you have at the time, and the budget you are under.No disrespect to anyone, it is my car and presumably I will sink or swim on the choices I make.Maybe I'll even learn something?

Keywords:daily driver,unknown bottom half,
tight budget, good power band with current cam,
not my first rodeo.

Again call Tim @ Bullet cams,I'd tell you which lobes to use but I would be attacked by the more lift .904 lobe crowd. With a hyd cam I do not agree that more is better unless the RPM's are kept low or your willing to go way out of your way for 5 hp. Tim has lobes that will not require valvetrain tricks,not cause noise as some cams do and make plenty of power. If you want a true .904 lobe he has them as well.

As for not choosing a cam based on a .904 lifter size? Those are very aggressive cams, and I would be very concerned about longevity and especially break in for one. Something based on a Ford diameter, maybe. But even something with a .904 tappet in mind, its going to gain him 15hp at best. Not worth the potential risk.
There is nothing wrong with the comp xe line. They are still far better and more aggressive than the average cam.
If there are any of the comp profiles that don't impress me, it is the hydraulic roller profiles.

Sixgun, just curious what rpm you shifted at with the 284. I would guess it liked 63-6400?
Also curious how far down the pistons are.

Nope.Have a 5,600 chip in it and haven't hit it yet in 8 months.
When I got it last year,thing was leaking oil,some from oil pump gasket, some from pan,some apparently from under heads (think the shim head gasket was losing oil as well as water )and I had very little confidence in it.When purchased (from a self-proclaimed "builder"no less)it had no bolts in the trans mount, the steering box was adjusted so far out the pitman arm rose up (WOW) so far the tie rod end was eating thru the nice hooker header, and the engine was resting on the drag link.No chip in the MSD at all.Slobbery rich Mighty D 850.Mostly bald BFGs in back.160 thermostat.Bad water pump.Guy was driving it around and had no clue all that stuff was messed up.
Now that I am in there,I see it seems to have some good pistons (no P/N), and always had good oil pressure (too much)
and is very clean inside with good cross hatch still visible on all bores, I think I'm OK to go on and put it back together and run it awhile.
You gotta understand when I say it ran "good",
my 1st string is a 452" six pack 4.10 4 speed .509 that used to run 12.80s in street trim,and my ex-race chall ran 11.40s with a 1.4 60 foot at 3500 lbs,4 speed, power windows and all.
Certainly not earth shattering in the company of those here, but I do know 'fast' from like my neighbors BS stock 350 80s camaro :-)
This 383 is the first one I've experienced that FEELS like a big block to me.
I will slide cal the piston depth tomorrow and let you know,as I am curious too.I can tell you it does not have much squeeze as it only pumped 135 psi (have to double check the shop wall, but thats what I remember)
That's part of the reason I considered the 284/484 9(or comparable)the upper limit for camming.Most of these mfgrs would like to see 160?
Thx, Bear

The beat goes on...
viperblue, as near as my uneducated eye can read my primitive tools,(slide cal,feeler gauges as a cross check)the pistons are about .043 down in the hole.
The dampener TDC mark is literally 30' off, is OK I have a replacement handy already,
BUT the messed up part is the power shaft bushing CAME OUT with the OP drive !!!???
I immediately started thinking about plan B,
(have a crusty "overhaul shop"steel crank .030 440 set aside, minimum rings and bearings)
But my machinist bud wants to take a look, may be able to fix in place in the car.We shall see...
made the decision, Comp 274 coming, KS 2110 gasket set also.Need to locate a powershaft bushing for a reference.Anyone know the shaft to bushing final clearance off hand?
Thanks, C

To install the bushing correctly, you need the tool on the left (the right hand tool is for removing the old bushing). After you drive the bushing in, as you pull the tool out, it will slightly expand the bushing to fit tightly in the block and also burnish the inside diameter for the correct fit.

Thank you, 413!
I just got through an exhaustive search on that, found out it cannot be bought locally at all, no one can cross the pioneer #, or even FIND this bushing in their parts books!
Ordered a pioneer from amazon which to all research is supposed to be a bang-in-and-it-fits deal.Will definitely check that, for sure.
Case

I use a stock oil pump drive to install the oil pump bushings, I drive the bushing in by using a long brass drift on top of the oil pump drive gear Works good, doesn't harm the bushings at all like trying to drive them in with the brass drift alone like I use to do You may want to use a file on the new Pioneer bushing to make a slight oil line across the top to allow oil to lube the bottom of the gear and bushing like the stocks one had It dosen't need to be very wide or deep, .020 by .015 or a little deeper

Very good, Mr.Cab, I will do that,sounds prudent.The one that spun in there also had a small groove down the bore,(vertically) ostensibly for the same reason.When I googled,I saw your old posts on this, took it all in, hoping for a trouble free fix.Bore still is round, as of last night,so awaiting the bushing.
Great talking to you,thanks for sharing what you know, not just about engines, either.
Aloha (for now...)
Bear

Case...

(Still like my 'old' purple shaft just fine)...

A little compression, a little converter, a little gear...

Boy... The negative stuff about Comp Cams... Last night I brought my new engine home. Yes, it has a XE274H in it. I sure hope those Chevy lobes don't tear the engine apart in the first hundred miles... Sheesh.

I chose that cam because everything I've heard nothing but positive about it. Word is it's a VERY good street cam. I'll let you know at the end of the month what I think once the engine is in and running.

It won't sound stock but maybe like a Singer sewing machine. Hope you love it.