motor is a 74 351W compression is around 8:1

670cfm Holley Street Avenger
RPM air-gap intake
1" 4 hole carb spacer
1 5/8" long tubes

would a 270S be too big for this engine??

I`d say it`s a little too big, but if you have decent rear gears it would get by. if you later did a rebuild with more compression and better flowing heads you would really notice a difference. but for a stock headed job like yours, I`d go with a smaller grind with more lift and duration on the exhaust side, since the exhaust ports are a nightmare in stock form.

well i figured when i had the intake off i would pull off the heads too and see how everything was, and give em a quick zap to clean up some of the casting flash at least (they will still be basically stock unless i get crazy) and maybe throw on some steel shim head gaskets to bump the cr a tad

a rebuild is in the works, but one that is done right is gonna cost a pretty penny, which i'm saving to paint the car too....

I'm not sure what you mean by a steal shim head gasket. Shim usually means you are going to increase the thickness. Why don't you just get a normal head gasket and have a machine shop mill your heads down to raise your compression. That is the best way to raise your compression.

That cam would be okay if you raised the compression above 9:1. Small Block Fords are lazy below 2,500 RPMs. With a cam that size you should have around 3.50 gears and a higher stall if you have an automatic. Mainly though it is the lack of compression that will make you engine bog down low.

Auto or standard? If it's a standard I do not think it is too much with the information you have provided. I had a 70 Nova with the original 307 2 barrel. I did basically what you are going to do, plus I had a Crower 280 hydraulic with a 4 speed. It really woke the 307 up, it was a solid mid 13 second car. I drove that car back and forth from Abilene Texas to Nederland Texas for two years every two weeks. It was a very strong running car and people who did not know me were never convinced it was just a 307.

Vince

it's an auto, the trans is a c6

i was under the impression you could get steel head gaskets that were super thin, if not i will just have the heads milled as suggested (although was trying to keep costs down)

edit : looked on summit and i was right, example here

A steel shim gasket is one used in place of a composite gasket to raise static compression ratio. This is because the shim gaskets are thinner like around .01 to .02 where the composites are around .04. The main problem with them is that if the block deck or head surface are a little off, it will be much more likely to leak. A composite gasket will allow some slop in the surface on typical street engines and still hold the gasket.

Chris

what is the maximum you can flat mill a stock 90* v8 head before you need to mill the intake as well??

I use the OEM steel shim type on a lot of SBCs,all of my engines that i own with steel heads i use the Marine Stainless Steel shim type less i need to lower comp.These are the only gasket that will last on my blower motors with cast heads and no o ring. Nothing wrong with the steel shims GM used them from the factory and they out lasted the rest of the motor!

When using the steel shim gaskets, you have to be very carefull that both surfaces are absolutely flat. The composite gaskets will alow for a liitle warp in the heads or block. That is why the come in most rebuild gasket sets.

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well i guess when i take the heads off to mill them and install the new gaskets i can check how straight the block is (since the heads should be perfect after milling)

About .028. Be carefull, as some heads are to thin at the decks to mill at all with out comprimising head gasket retention. Utilizing a steel or aluminum shim will only compound the problem.

but even if i were to use a normal gasket instead of the thinner it would still bump the cr enough to make a difference