587 heads any good? Smog?

[LXguy]

Hey All:

I found a 360 here locally. Seems decent enough. It has heads with casting number 3671587 on them. It's a 74 motor. The info I've been able to find on the web says these are smog heads, but there aren't any smog holes below the exhaust ports.

Looking to build a motor to 350-375 horsepower. Would these heads be able to support that, or should I plan on adding heads to my budget?

Thanks!

Steve

 

[goldduster318]

They're about par for the course as far as pre-magnum small block heads go. The only heads that are really any better are the 340 "X" heads and the "308" swirl port heads.

I sold one of these to a guy on here about a month back, he really wanted it...but I couldn't really see any difference between it and my other mismatched head that is a 4026587

You'll probably have to do some mild port work to get the engine to that power level...and change the pistons to raise the compression. Your other option with stock pistons is to go to magnum heads...I have a totally smogger engine and its really "woken up" by the magnum heads.

 

[moper]

Any head including the small port 318 heads will reach that level without porting but with a good performance (5 angle) valve job. The 587s are as said, just a later J head IIRC with the pad the the AIR injection system. Soem heads are drilled for that, some are not. A 360 with a midium sized cam will make 350hp with no porting work.