hi. im going to start swaping my stock tbi 305 heads for some vortec heads.
other than intake and egr issues is there anything else...ANYTHING ANYTHING.....that i should know....
im going to use the same rocker arms,valve springs,and push rods because they are comp cam performance parts.
what head gaskets do i need?? do i buy them for vortec heads, or for 91 tbi 5.0 motor?? part numbers would help.
thanks guys.

 

Vortec heads use self aligning rocker arms: Comp Cams 1.5:1 rocker arms PN 1417-16 or GM stamped pieces Stock Vortec heads come with pressed-in 3/8-inch rocker studs and do not use guideplates. Stock Vortec heads are limited to 0.475 lift! Do not use 1.6:1 rocker arms as stock Vortec heads will not benefit from increased valve lift. You should check your springs for binding if you have a cam that is anywhere close to this limit (0.450+)! Both Fel-Pro PN 1255 and GM PN 12529094 make intake gaskets to fit the Vortec heads.

 

The rocker arms are 1.5 and they are self aligning. They are from 91 tbi head though I compared. Them with the rocker arms that the vortec came with and they look like they will work. Thanks for the intake gasket part number does anyone know what HEAD Gasket to use?

 

Look for a small bore gasket with small compressed volume to maintain compression. One possibility is SCE 011854 with 8.20cc compressed volume and 0.043 compressed height. Another possibility is Fel Pro HD Q505SD. There is not much difference in terms of gaskets used between L30 and earlier Gen 1 305 engines.

//RF

 

I heard there was a difference between the tbi gasket and the vortec gasket in the way that the coolant flows. One has a passage that the other one does not.

 

Seems small.... I didn't really think about it at first.... Throttle cable bracket!

All the holes end up in the wrong place, and the angles are all wrong. Had to totally fab mine up. That's based on my using an Edelbrock intake. YMMV.

As mentioned - watch that NET valve lift. It's not so much the coil bind (that's easy to see) - it's that the retainer will smash into the valve stem seal and squish it to death over about (and this number varies) .475" lift. It's cheap and easy to fix while the heads are off (ie, NOW).

I had mine done, so I'm good for like .600" now.

edit: If you find out something on the head gaskets let me know! I bought the ones for the block which was a '90 TBI 350. Got a few thousand KM's on it now, and have had no overheating issues Remember to add the bypass hose from the front of the manifold to the water pump. Sure fire overheat without it.