Some 66 Questions...

[Guest drewriviera]

Hey guys! I am about to redo the drivetrain in my 66. I have to get a set of custom pistons made for my 425 and I have to know the stock combustion chamber size. I cannot find that info anywhere! I am trying to get my measurements to make some 11:1 pistons.

The ST400 that's in my car. Does this transmission have the same internals as a standard Turbo 400 or is the only difference the torque converter?

The last thing I needed to know was if they made a 66 model without a/c and what the block off plates looked like if they did?

Thanks

-Andrew Allman

#11851

[JZRIV]

Andrew,

Can't help with the combustion chamber size but companies that make pistons for the 425 should be able to offer some assistance. Try checking over at V8buick.com. You might find a lead there. There are people that build these engines for racing and I'd try to find one of them.

The variable (switch) pitch is relative to the tranny design and not just the converter. There is some good info on these at buickperformance.com

Yes there were non A/C cars. There is a 66 on ebay right now without A/C so you can check out the pics and see what it looks like. There is still a box there for the heater core.

[RivNut]

The big internal difference is the main input shaft that, when activated by the internal solenoid, changes the angles on the vanes of the torque converter (switch the pitch), but shift kits, etc. are the same for the ST400's as for other TH400's.

[austingta]

Here is a pic of my 66 GS non AC engine bay. HTH.

Frank in Austin

[riv1964]

CC's on Nailhead Combustion chambers:

varied between 125-127cc

Mine with a "clean up mill" are at 123-124

Roger