I try to.. if the head peaks at .600 and you run
.700 lift it sees that .600 twice with the time
in between.. if you go .600 it sees it once and for
only a short period of time... specially on a limited
head you need more time to get the A/F in there at the
upper RPM when things are happening fast

I guess old age is setting in for me, cuz I wouldn't run a cam that big in anything I had to use as real "transportation".
Those cams would be fine if it was an open header bracket car, but I'd scàle it back a little for closed exhaust if it were mine.
But, I'll admit my tolerance for poor street manners have dropped quite a bit in the last 10 years or so.

For an "off the shelf" cam for that combo, something like a Hughes 6872 is about as big as I'd go, with street duty in mind.

Come on Fast, you`re not gettin older just WISER.......... I drive my dart quite a bit and have no issues w/276-281 @ .050 and 97 degrees of overlap and runs/drives fine on junk Cally 91 and idles nice and clean thankxxx to my carb guy...........

I ran the numbers thru Controlled Induction and it agrees with Hughes 6872 for that combo.

If you go too big on the cam you'll lose the bottom end torque but you'll never reach the full power potential of the big cam since your heads aren't really big enough for the engine. So the big cam kills it down low and the small heads kill it up top. Been there and done that a bunch of times myself.

Thanks guys , Dwayne and Andy .
Doug , i have gone high 10.80's with current 440 . That only runs .520 net lift 258@050 cam . 505ci - got to gave a goal

Tex

I don't see why you couldn't run 10.50 pretty easily actually.. You stated you have already been in the 80s. The cam you have currently sounds like it's pretty decent. If only it had more lift. I would aim for as much lift as possible. A wider lsa has better street manners. If you can get a solid 11.1-11.5:1 cr, a good ported intake manifold, and rest of the combo to match I think you'll get there. With the bigger ci you can shift 5,500-5,800 and it will work out decently. Keep cam on the lower side @ .050 like you have, advance it even, it will work. A 1,000 cfm carb should be about perfect. Get the right primary size, length, etc right to maximize combo. Matching combo, attention to detail, and some decent parts will get you there.

Been given some great replies here Tex, I'm not great at picking cams so have shut up here, only thing would say is sell the heads and buy some Trick Flows

I know just what Dwayne means as I like my 63 so much better with the full tailpipes all the way out the back. The car is not as loud and thats fine for me as I like the sound of a capped up hotrod that dont give me a headache but still sounds nice when I lay into it. Guess I have mellowed out some myself. Ron

Al , yes all great help
Not sure if changing from full CNC stealths to Trickflows is it. If i swapped heads i think Indy EZ with a MW port would be my choice
Well roll on the short block.

Tex

What do your heads flow Tex ? Trick Flows are around 330 with stock port. I want some for the young blokes VG Valiant.

Al
315@600 , 320@650
That is quoted numbers as heads done by Modern

Tex

Ahhh OK That's better than I thought they would be.

What are the upgrade differences from your 10.88@122 combo? To go 10.50 you need an additional 60-70 hp.
Doug

If this is really a daily driver, you don't want the most aggressive lobes. Those will beat up springs and valve jobs faster.

Not sure what my e-brocks flow now but going from ported 906`s and a solid 590-605 Isky cam to my stage one ported rpm`s and an Isky .680-.660 solid roller took me from 10.40`s to 9.90`s then I added a 2.19 intake valve and super ported the rpm`s and went 9.79 first pass of the trailer w/way more left........

Looks to me like it's about 60 cubes, better heads and at least 10deg more duration with close to .100 more lift.
A 60-70hp gain seems well within reach.

Smallish intake port with good velocity so i might lean closer to a single pattern of around 278 @.050 but maybe a wider 109-110 split since overlap will not be your friend on the big end and put it in around 104-105. Cab makes a good point about tying to use it all up before the small port velocity becomes a restriction but by the same token torque won't be an issue with that many cubes and stall.

I would look to Dwayne to cut you a fairly agressive at .200 but still streetable .875 base circle solid lobe but to me that combo cries out for a roller since it would benefit from a lobe that can park it at or near peak lift rather than have to go up past and over to get the same effective duration with a solid flat tappet.

I have a 264/268 @ .050 hydraulic roller on 108 in at 102 in my 11.7:1 517 max wedge and its perfectly streetable to 7K with great flowing CNC Chapman max wedge heads. So that would compare to about a 274/278 @ .050 solid flat tappet profile, at least off idle and in terms of RPM range.

Regardless on cam you're going to have a 'saturation' point rpm with a small port and modest compression on a big cube motor. Going too big ( past a certain point) can cost you drivability at a greater offset than your gain in power.

I think dwayne had a couple cams for sale, one of them i had my eye on, that might be close, dont forget that with a solid roller you can generally regrind them about ten degrees at .050 and 2 degrees tighter or looser by going to a smaller base circle for about $125 bucks or so.

Doug ,
55ci , bigger cam especially lift and possibly fitting a dominator over the 4150 hp1000 . Though that may not be the big gainer .

Tex

Brad ,
That is something to think of , thanks
Wize ,
Roller isnt in my future though i know i may give up some hp . Cost is a big decider , Aussie peso is 2/3 US $ . But also simple and reliable

Tex