rocker arm interchange

[ciffer]

I have a set of 1.5:1 aluminum roller rockers on some spare heads. They are stud mount. I do not know much about the heads other than they are crappy iron casting from the 70s mounted on a 302/327/350 block.

Can I install them on my stockish 88 TBI roller engine?

 

[63chevyll]

I would say no, unless you have guide plates.

Centerbolt heads requires self aligning rockers.
If you look close at the end of the rocker where it opens the valve there are little outward spots the keep the rocker straight. On stock heads

 

[4X4HIGH]

There was some crossover between when GM used the non self aligning rockers versus the self aligning rockers so I would need to see a pic of the heads you want to run them on where the pushrod goes through the head. If the hole is round then you need self aligning rockers and if the hole is rectangal then standard old rocker arms will work.

Also, none of the 87-95 TBI blocks came factory with a roller cam although most were set-up to accept one.

 

[82355]

They are probably too thick to fit between your stock valve cover's inner bracing.

Martin

 

[sweetk30]

isnt the press in studs not good to use with polly lock nuts used on full roller rockers ?

 

[82355]

I've done it with no problems, as have many others.

Martin

 

[pmpski_1]

Also, none of the 87-95 TBI blocks came factory with a roller cam although most were set-up to accept one.

So these are all flat tappet cams? Why would the factory provision a block for a roller cam and not ship them that way? The roller cam was just another reason I picked up a 91.

Darn. Here's to hoping the PO used the right oil or put a zinc additive in it. At least I know now. Guess I should have done a bit more homework.

 

[4X4HIGH]

So these are all flat tappet cams? Why would the factory provision a block for a roller cam and not ship them that way? The roller cam was just another reason I picked up a 91.

Darn. Here's to hoping the PO used the right oil or put a zinc additive in it. At least I know now. Guess I should have done a bit more homework.

Yes, ALL TBI TRUCK engines (I should have specified truck in my original response) from 87-95 are flat tappet hydraulic cams, the cars starting getting the roller cams in 1987 though and the trucks didn't see them until the vortec came out in 1996.

 

[79rustyk10]

Ive made some pretty good money selling the "crappy" 70's heads to the circle track guys who have rules on what heads to run.

Ive also used non self aligning rockers on TBI heads. What scott says is true, if the hole is rectange shaped, the sides of the holes are the pushrod guides. If they are round, you need the self aligning rockers or guideplates. guideplates are not worth the hassle on a stock TBI engine.

 

[4X4HIGH]

Guide plates also require screw-in studs and maching of the rocker stud bosses AND hardened pushrods for use with guide plates.