For sure........ it’s knowing just how big is big enough without being too big😬

Not to beat a dead horse, but what pistons? You/someone would need to have purchased a domed high compression piston which are normally reserved for racing. You cannot mill 906 heads and deck the block to 11.2 CR with a typical replacement type piston.

That is why I recommended what I did. The intake is done at 5000. I don't mean its past peak, I mean done. To maximize usable power, probably a cam that peaks at 4500 to 4600 rpm.

Change the intake, totally different game.

I’d be looking for a ch4b.
It wouldn’t be night and day....... but it would be something, and basically looks stock.

I'd just stick a 509 in it with the stick shift it should work good
Gus

I was thinking; do we know what cam is in the engine now? or are we assuming a stock magnum cam?

Not sure, I let the engine builder buy them and that's the CR he told me. I can tell you it doesn't like pump gas!!

It has a COMP Cam XE268H high energy, which was OK. Just wondering if there's something better.

Neither does mine, lugged in 4th it sounds like a paint can on straight pump gas. However it takes so little to get it to stop. 1 gallon of race stuff to five gallons pump quiets it right up.

from my experience I don't like a comp cams 268 anything in a 440. for example; going from a comp cams 268/276 to a mopar 272/.455 I picked up 2-3mph in the quarter with a stock type engine. those 268's are 110lsa with 4 degrees of advance no matter what flavor you buy. they close the intake valve way too early. a cheapo summit 6401 is a better cam for what your doing. there are some lobes out there that may improve on the summit but will need to be custom ground.

Not a product bash by any means....... more of a “heads up” for whom it may concern.

The big Summit cam is a tried and true White Box cam in a 440......as well as other makes and families of engines.
One of my friends was freshening a 455 Pontiac for a customer of his, asked about a good off the shelf cam for the motor, and I suggested that same grind.
He got it, put it in...... motor ran decent enough with it.
Well, someone didn’t do a good enough job checking the condition of the rod bores and/or clearances, and within 50 miles it sounded like a rod bearing was failing.

Pulls it apart, sure enough a rod bearing is going away(not spun, but down to copper all the way around).

He gets to looking things over and is concerned with one of the cam lobes.
Says the corresponding lifter looks fine, but doesn’t like the lobe.
He brings it over for me to look at, sure enough that lobe has started to go.
It’s got about .010 or so missing off the nose.

I could’ve dismissed it as poor assembly or break in practices except for what I saw on the other 15 lobes.
The lifter wear track was right down the center of the lobe. This lead me to put the cam in the lathe and measure the lifter taper.
Indicating across the bearing journals showed basically zero movement, then checking 8-10 various lobes showed what I suspected by seeing the centered wear pattern....... less than .001 lobe taper.
Most performance cams have between .0015-.0020 lobe taper.
The reduced taper resulted in the lifters having contact basically at the center of the crown, which results in poor lifter rotation.

The other issue I found and didn’t care for was there was quite a bit of chatter all the way around the lobes........ with the wear pattern having a railroad track look to it.

I’ve used those cams in the past with pretty good results, but after seeing that....... I won’t anymore.

I got a custom Comp for that 455, a little bigger....... it had .002 lobe taper...... good lifter rotation...... no issues with that one.

howards has lobes that would be more accurate for duplicating the summit cam. intake lobe 1hf225310/exhaust lobe 1hf235325.


my experience with the stock/near stock engines is to get the intake valve to close at 70, or a little more, degrees ABDC. the summit cam closes at 72ABDC according to my notes. the 268 comp is 60ABDC.

A couple years ago we put a Howard’s 720141-12 in a fresh 440-6 rebuild.

It worked well enough but there might have been a few hp left on the table.
Made like 410hp with headers(manifolds in the car).

I can attest to this.I have a ch4b on my well ported iron headed 496 with an older Hughes Engines solid lifter cam(smallest solid they made at the time).I did send the intake to Hughes for their "deep port match".All this was done 20 years ago it seems.

That intake has no problem turning 6k rpm and pulling to it in my 496.

lots of good hints
The Nostalgia plus may be OK, maybe not - Duration may be too big for your driving style and build- maybe not
lobe centers may be too narrow for that CR- essentially a repop of the Direct Connection/ Racer Brown 284 cam
but I'd be looking at the XE275HL series if comp cams is your thing- and what they have may or may not be OK
The 268 most likely too small with that compression and it's not optimized for Mopar in the first place
U have a unique combination
I'd contact Racer Brown and Bullet/Ultradine lots more Hyd selections as does Howard
key is getting advise from the grinder for your combination
Lunati Voodoo is always a good call for MOPARS
agree on holding down overlap
really easy to give up the low end without having the flow or revs to have a big top end so build an "Engine Masters" type torque curve