Thread: almos have all my engine stuff

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Here's what I have. I have a 1979 350, Edelbrock600 cfm carb, comp 270h-10, new lifters, new springs, new double roller timing chain, holley street dominator 300-38 intake, and a new holley mechanical fuel pump. Should I keep my 350 heads or switch to my 305 heads? About how much would this combo be worth as far as h.p. ?

Well, here's the lineup for the '79 motors......
L39 305 145 hp
Z28 350 175 hp
Corvette 350 225 hp

Since you have little more than a stock rebuild with the exception of the cam, I'd say you might be adding about 30 hp. The Holley manifold is little better than stock in my opinion, since it is a low-riser design. Of course, it'll be lighter than a cast iron manifold.

Hold the 305 heads for your next 267 buildup.

Switching to 305 heads will help compression. I think it will still be choking the motor in the stock configuration however. They wont flow what you need. You can pick up some L98 aluminum heads pretty cheap. Just port em and burn rubber.

The 305 heads will render the motor incapable of operating on pump gas.

what wuold 305 heads bring the cr up to?

10.96 figuring zero deck and 4 cc's in the pistons.

that is kinda high what's the highest compression that can be run on pump gas. I know of 4 cylinders with 10.5:1 on premium unleaded.

With steel heads and 93 octane, 9.0-9.5. The four cylinders you mention are probably computer controlled with aluminum heads. Fuel injection, Al heads and a computer let you run 10.0 - 10.5, depending on the engine set-up.

cool didn't know that, yeah it was on a 2.3L H.O. quad 4. So the aluminum lets you run higher compression because of heat dissapation?

Yep.

cast iron heads detain heat more causing the a/f mixture to detonate eariler, nifty