could use some advice on a 454 -

[aaronkl84corvett]

car is a 70 Monte - original LS5 car, TH400, and 3.31 gears - the previous owner kept everything OE, but put speed pro flattops in it - with the stock 290 heads... no matter what I do, its just too low compression to make any power... from my math, its likely in the 7s.

anyhow - i'm having a set of closed chamber ovalports finished up now... they measure 94.2 CC - have 2.190 intake valves, and with 1.720 exhaust valves. I had hoped to get to about 10.5:1 compression and run the old L72/LS6 cam....

in fact, i had cliff ruggles calibrate the qjet for that very combo.... but after doing all the math (unless I'm missing something) i'm gonna wind up around 9.5:1 - i'm just not sure how happy that cam is gonna be in a lower compression, heavy car.

I suspect i'll have to go with a looser converter, but really - does anyone see any serious driveability problems, or should i scrap the LS6 cam all toghether

the car has the log type manifolds on it - and has a full exhaust of course - it is more of a restoration cruiser - but i certainly want it to run better than it did at 7.5:1 with the LS5 camshaft.... incidentally before sending these other closed chamber heads over to be rebuild, I tried using a Howards Hyd Roller cam - (spent a lil money - hoping i could get around the compression issue) - awful mistake and total waste of money - the car ran worse, that cam was 225-231, 567-578, 112 LSA - they said it'd be just fine wit 8:1 - but truely it wasn't - just don't want to make the same mistake.... and frankly, i really prefer the GM grinds as they just flat work with stock type heads/intake.

Any advice?
Cheers