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I'm ready to start assembly of a 1976 360 block for my 71 Demon. Got it punched 30 over and bought stock dished pistons which are only rated at 8 to 1 compression. I wonder if I made a mistake there, since I bought a summit racing cam with 284 advertised duration (228 @ .050).

This engine will be pretty much stock except for the cam, double roller timing chain, and hi volume oil pump, so I'm worried about the lumpy cam I bought. I read that I should be going with 9 to 1 compression with this cam. Am I going to bend my valves or pushrods?
Should I exchange these pistons before its too late?

I'm building this engine for street use. Of course I want good power but it doesn't need to be super fast. A 14 second qurter would be nice. I've got an aluminum intake and 4 bbl Holley for the top.

Any suggestions are appreciated! This is the first v8 I've built myself.

Also - I'm getting the heads redone: Is it worth the extra money to get the intake valves widened to 2.02? They are stock 1.88 right now.

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8 to 1 compression isn't going to cut it with this cam. 9 to 1, is more realistic. The compression you now have would make decent power
with a cam closer to the 340 cam specs. If you decide to ditch the "lumpy" cam, you may need to make a few KEY adjustments to the engine with a "smaller" cam. Yes, the intakes CAN be widened
to 2.02. It, will benefit you later on, IF you decide go back with the higher compression and "lumpy" cam. But for now, weigh the price of new 9 to 1 pistons, rings and prep work AGAINST a complete cam kit (preferably around 215-220 degrees @ .050 on the intake) for your engine. BTW
what kind of intake manifold and size of Holley carb?

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8.1 = too low for anything other than a stock type cam.

Do you really know that is what the compression ratio is? Have you measured the piston dish volume, how far the pistons will be down in the bores, the true combustion chamber volume of your heads, etc? Are you having the block deck surface cut down, milling the heads, running a thinner gasket?

There is a handy compression ratio calculator on the KB Pistons website to help you figure out what your compression ratio is.

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Great points, but according to Dughuff, he wants a street car capable of running a solid 14-sec quarter. Sounds to me like a "well tuned" stocker setup!!
A bit of "340 type" hardware will get the job done for a little less than what he thinks. And on his CURRENT compression too!!

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compression wont bother that cam
not rocket science here
ive put that motor together 4000 #
car 391 gears , header STOCK HEADS
torker 360 intake
nothin converter
600 holley and run 14.20s
drove it everday to work
COME ON !!!!
wish i had 3200 car to put it in

built that back in 1992
75 road runner
car still going , same motor!!
run low 13 high 12 easy

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That's good. The 3.91's and the 600 Holley seemed
to work good together along with the intake manifold/exhaust system. (Probably MUCH higher velocity acting on the venturi's) And that 3.58" arm provided the oomph to reach it's range where the cam kicks in. OK, I'll buy it!
Marginal to say the least, but do-able!
I would go a different route with two tons of car.
Stroker SB or BB.

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the other post he started has more technical discussion and suggestions, but realistically to be a solid 14 second car with (I presume) 3.23's or so, a stock long block 360 with a 600 cfm carb, eddie air gap, headers, a factory high stall converter or MP166K converter and a comp XE262 will get you there in an A body and be happy as a clam on 85+ octane...fuel economy won't be the best though.

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I believe with a BIT of ignition/carb tuning, he
WILL have decent gas mileage. The KEY is to make the parts compatible to work TOGETHER!!