Max lift

[coyote42]

What is the max lift you can use on stock la318 heads? 302 or magnum.

 

[805moparkid]

with no valve to piston issues?

 

[Abodybomber]

Magnum heads .525"-.530",using Hughes 1110 springs & matching retainers. The valve guide needs to be trimmed shorter after that. No answer on LA heads.

 

[txstang84]

My brother measured the distance between retainers and guides on his J heads and came up with .480"

 

[moper]

For LAs - The older books say .520 without problems but I tend to think that's advertised lift - not actual lift at the valve. The MP .509 will work but in a standard LA engine that only has about .490 at the valve. I'd say stick with less than .500 advertised and you won't have problems.

 

[UOP]

A buddy is running .539/.539 lift in a stock shortblock 5.9 magnum. Stock heads are ported and valve guides are cut but no ptv issues. Not stock rockers though.

 

[Abodybomber]

Good to know. A really nice lift, for ported Magnums.

 

[74Dusted]

I measured .520 on a set of stock J Heads, any more than .520 and the retainer would touch the valve seal.

 

[65TerrorCuda]

Pretty close to hitting the retainers at .420 lift cam. Ymmv
302 head with crane springs etc.
Had to shorten guides

 

[coyote42]

Pretty close to hitting the retainers at .420 lift cam. Ymmv
302 head with crane springs etc.
Had to shorten guides

Have 302 heads on the 318 now. Don't want to change heads or modify at this time. Was it .420 or .520 lift? 420 max seems really low. Thanks

 

[65TerrorCuda]

It was .420 lift, I think you could get more if using the stock(roller) springs and retainers, but they were weak so I reused my Cranes from the previous 273 heads.