[TA63]

Anyone have the jig for performing this step they would be willing to rent?

[FrankieT/A]

There is no jig. Plus they really should not need elongated if you use 5/16 push rods. The only reason they are elongated on Ram Air IV is because RA IV have 11/32 push rods.

[Formulajones]

There are drill jigs made to do this on some engines. I think it's called a louis tool? It's relatively inexpensive. I have one here somewhere for SBC heads. Unfortunately as far as I know you Pontiac guys don't get one. At least not that I've seen anyway.

[Formulas]

There is / was one for Pontiac produced by Paul Spotts, two versions soft and hardened
I bought the soft one and it didnt last long because of side loading of the cutter

If i was to buy another one i would work the slot by other means and use his tool as a go no go guage so you know when your done and dont get any surprizes after the head is already on

[Half-Inch Stud]

Spot Eye by Paul is a fixture that does the oval. I used a grinder and rattail file

[Skip Fix]

Originally Posted by Formulas

There is / was one for Pontiac produced by Paul Spotts, two versions soft and hardened
I bought the soft one and it didnt last long because of side loading of the cutter

If i was to buy another one i would work the slot by other means and use his tool as a go no go guage so you know when your done and dont get any surprizes after the head is already on

Yea on the 400 in the 81 TA I THOUGHT I had ground enough! Had already torques heads down. Had to stay with 1.5s. I used Spotts tool on another set of heads-not used yet and it takes a lotmore in the middle-where my grind job failed. A drill press and some angled shims can get it done , a Bridgeport would be easy to get the angle right.

[ponjohn]

Spotts has the tool.

[steve25]

If you not porting the heads / opening up the push rod pinch then just run a 1/2” drill bit down thru the 4 push rod holes in each head that are the tallest.

In 10 minutes your done!

[ta man]

Originally Posted by Half-Inch Stud

Spot Eye by Paul is a fixture that does the oval. I used a grinder and rattail file

Rattail file works great for the final bit of clearance.

[TA63]

Originally Posted by steve25

If you not porting the heads / opening up the push rod pinch then just run a 1/2” drill bit down thru the 4 push rod holes in each head that are the tallest.

In 10 minutes your done!

This is great to know Steve. I did a little port work, but it was almost exclusively in the bowl area., and widening of the port floor.

[steve25]

You can still widen the pinch like.035" and run down a1/2" bit without going thru the casting.

You will however need a strong drill.

A 3/8" chuck model and one of those 1/2" bits that neck down to 3/8" will not get it done unles you use intermediate size bit before the 1/2".

If you still want more clearance at the top and have a chamfer bit or a unibit then use that some at the very top of the hole.