[khogan]

I'm having Greg Merrick do the heads on the 389 from my '66 GTO. Turns out the cylinder walls have some pitting - mechanic speculates old rust problem. Anyway, now I guess we're looking at having someone bore it out. Beside new pistons, what else should I think about doing. This is/will be a mild street/daily driver. Suggestions on any of this is greatly appreciated.

Greg could also do the block work, but because he is booked so far ahead, he couldn't get to it until March. Would it be important to have the same guy doing the heads also do the rest rest of the engine? Is there another good Pontiac engine builder in the Denver-Boulder-Longmont area of Colorado?

Thanks for all input.
Ke

[khogan]

I'm having Greg Merrick do the heads on the 389 from my '66 GTO. Turns out the cylinder walls have some pitting - mechanic speculates old rust problem. Anyway, now I guess we're looking at having someone bore it out. Beside new pistons, what else should I think about doing. This is/will be a mild street/daily driver. Suggestions on any of this is greatly appreciated.

Greg could also do the block work, but because he is booked so far ahead, he couldn't get to it until March. Would it be important to have the same guy doing the heads also do the rest rest of the engine? Is there another good Pontiac engine builder in the Denver-Boulder-Longmont area of Colorado?

Thanks for all input.
Ke

[khogan]

No input on this?

[Tom Vaught]

A .060 overbore will clean up most deep pits.

By boring .060 overbore you can use replacement
pistons (cast ones) that have a double valve relief configuration for either 389 heads or 400 pontiac heads. If you decide to upgrade to 400
type heads the standard bore 2262 TRW/ Sealed
power/ Federal Mogal pistons are the ones to use.

I have a new set of either pistons if you cannot
find them elsewhere. The pistons and the crank will need to be rebalanced for the 400 piston weight. Good luck. Tom V.

ps My 389 GTO engine is .060 overbore.

[khogan]

Thanks Tom
This is exactly the kind of input I was looking for. I'm thinking while I'm at it, I should use pistons that allow me to reduce compression so it will run better on pump gas. Would 9.5/1 be a good ratio?
Ken

[llucas]

If Greg hasn't started on your heads and you are not absolutely tied to using the '66 heads, you should think about going to later big valve heads and pick up the extra performance and somewhat larger chambers. With 72 cc combustion chambers and dished TRW 2262's you can get the compression down to 9.5 to 1 and your engine and you will both be a lot happier on premium pump gas. Just a thought.
p.s. I did this to my '65 with 1968 #62 heads ported by Jim Butler and TRW 2262's dished by him along with an Ultradyne 280/288 cam and I really like the way my car runs and I still get about 16 MPG on the highway with Tri-Power.

[Tom Vaught]

If you use a modified 2262 piston like Ken Crocie originally did and Butler and everyone has copied
you should have a lower compression ratio and be able to run either the 389 heads or the 400 type
heads. Tom V.