i bought the truck already built, heres what the previous owner had to say about the engine:

Block was fully prepped, bored .030, decked, align honed, etc..
Crank is stock with I think standard journals.
Stock rods shot peened, ARP bolts
New pistons – Don’t remember mfr or ring specs. Probably around 10:1.
Everything balanced
Cam is a GK A6HZ84P 230@.50, 284 adv / .470 109 CL. Notes indicate it degreed in at 107 and no additional offset.
MP lifters and pushrods
Roller chain, Melling HV pump, MP windage tray.

Heads are Mopar smog prepped by Hensley Racing in Knoxville, TN.
Glass bead, magnuflux, Milled .010, new guides, new seats, new locks, 10 degree retainers
2.02 / 1.60 valves
Don't remember chamber volume.
Unknown springs – maybe MP but don’t remember for sure.
Spring installed height 1.65 at 100 lbs seat pressure – Coil bind at 1.10
No additional machine work other than mill and cut for the 2.02 valves – no port work.

Never had it on the dyno, but similar engines I’ve built come in at around 375 hp.




ok, now my question is if i switch to edelbrock RPM heads (LA style) whats my compression ratio going to be? can i still run pump gas? also with an air gap intake (already on the truck) and a holley 750 with full length headers whats my power going to jump up to with those heads??

can't know what your new compression ratio will be without you actually knowing what your current ratio is .

Quote:

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PROBABLY around 10:1

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AND

Quote:

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Don't remember chamber volume.

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its a stock smog head with bigger valves no port work and they have been milled .010

im just looking for a ballpark figure here. i think stock heads have 72cc chambers so milled .010 lets say 69cc-70cc? now drop that down to a 63cc chamber assuming im at 10:1 what will the compression ratio end up at? id like to be able to run 93 octane and if those heads are going to make that not possible i probley wont do it

anybody?

compression going fro ~70 to ~63cc will increase approx. .6:1

93 octane should be fine with that combo if you have good quench. how much performance difference? hard to say, depends on how good the prep work on the iron heads are. the .6:1 compression increase alone is probably worth about 1.5-2% more power.

Compression will probably go up arond 1/2 a point, but since they're aluminum instead of cast iron, you will still be able to run the same octane fuel as before.

The short answer is that not only will they run on the same fuel they might run OK on one grade less.
R.