Joined: Thu Dec 13 2007, 03:25PM
Location: Germany
Posts: 19
Hey experts!
I got myself some 74 small block heads and they went on my 68 318 with an Edelbrock intake along with an Edelbrock carb. Now people are telling me that this combination results in a low compression engine. Checking on the compression, all the cylinders had 115 to 120 psi of pressure which I believe is really too low. Now the idea is to mill a bit off the heads to improve on that. Does anyone have any experience with that? A good mechanic told me, milling off 0.05" equals roughly +14 psi. I'd probably take a little more off, but don't know how far I can go...
It is true that if you bolt the 340 or 360 Heads to an LA-318 Block you will have an lower Compression Ratio. No amount of milling will aide you. !study
Use a set of Standard size 360 Intake and Exhaust Valves on your LA-318 Heads. !think
Check to see if the In-take Manifold to Head Port size is the same size. If you have an 340 or 360 Intake Manifold the Port Size is much larger than any LA-318's ( think of an 19mm Pipe into an 13mm hole ). The only OEM size that truly matches is the late ( last ) series LA-273 4 bbl In-take to any LA-318. !study