basically a flat top LS5 - but with a set of 67 702 small chamber heads -
has 2.19/1.76 valves in it and the LS6 springs/retainers - i'm seeting 125 on the seat and abotu 315 open at .520 lift.

I have a Howards hyd roller on the shelf that is 225/231 at .050 - 277-283 at .000, with .567 and .578 on a ICL is 108, LSA is 112....

but an engine builder friend is strongly recommending a Comp Marine HYD Roller - (01-451-8) which measures at 230/236 at .050, 284/290 adv ( i believe this is at .006 not .000) ICL is 110, and LSA is 112

Compression on the 454 should be around 9.5-9.75 - I believe the pistons in it are the 71/72 LS5 flat tops, No domes/single valve reliefs - and the heads CCed at 94.2 - and I have a .018 shim head gasket (block is .010 over - stock deck height -

running the stock iron/qjet intake and stock manifolds.

from the specs... the Howards is a bit smaller on the duration, but by the valve lift, looks like as that valve starts to open, it opens faster and definitely has more lift - probably stays open longer above .200 as well.

any suggestions as to which would be the better street cam -

rest of the cars specs are TH400, holeshot 2400 converter, 3.31 gears.


I really wanted to run the OE solid LS6 cam - but i'm afraid it might be too much - and not enough compression. Any advice?

 

I think either of those choices would work fine...Probably neither is ideal but....Since you have the howards, you could certainly try it.

I do know for a fact you don't have enough spring pressure for either one...thats for sure.

With the stock intake/exhaust manifolds and a relatively tight converter with tall gears, I'd probably lean towards the Howards 225/231.

I'm sure the cam gurus will be in before long to give you a better recommendation and sell you a cam.

I'd be willing to bet that for your basically stock type build, the howards cam would work great...



FWIW, I have a .030 454, flat top pistons with lightly ported #215, closed chamber ovals. Performer intake, stock chevelle exhaust manifolds and an old school Comp 270H hyd flat tappet (224*/.515"/110lsa) and its a VERY torquey, nice driving street combo..but it is DONE making power at 5200 and signs off at 5500..

It has great manners, basically drives like stock but with a little lope at idle. It would work great with a stock converter and stock gears.

So my point is, anything in a HYD roller that is even remotely comparable would work well for a cruiser.

I'd be willing to bet that Howards cam would work ok.


Here is another recommendation for you if you really want to ring as much top end power out of it as you can with the parts you have....Obviouisly headers would be a big improvement. If anything, run the stock cast manifolds with a GOOD 2.5" under car exhaust system.

http://www.claysmithcams.com/bbc-454...x-of-5700-rpm/

 

The Howards is a better cam for your combo.

It's actually a pretty good looking grind. I would move the lobe centers around if I were custom grinding something but the seat and .050 durations as well as the valve lift would be very similar.

Don't expect a big lick at idle or explosive power once you get some RPM.... that Howards cam will have a little lope at 750RPM and pull hard from 1500RPM. Probally tap out at 5500RPM or so....

You don't have alot of compression or very good induction with the factory GM QJet intake, plus the tall gear and tight converter. More seat timing on those lobe centers are the last thing you need in a cam.

As ajrothm said - I don't think those valve springs are going to handle a BBC hyd roller.... the valves and lifters are heavy as hell.
Will