Usable blocks?

[TheNovaMan]

I'm sorta new to turbo Buick tech, so forgive me if this is a dumb question. I just read an article in Hemmings Rods & Performance that said turbo blocks don't have any more nickel and aren't any stronger than regular 3.8s. It seems the only difference was a threaded hole for the oil from the trubo. They also said a 4.1 V6 was an option (not turbo) for Buicks starting in 1981, and recommended using any 1977-1987 block (even-fire) for performance buildups. Their sources were Jack Merkel and Ron's Custom Automotive Service. Anyone want to confirm, deny, or add to this info?

 

[turbodave231]

You got good information. Production blocks are relatively all the same in strength. No special iron, no additional metal in turbo applications.

However there was a significant change in 1986 to the head bolt location in the production blocks. The head bolt threads were recessed well below the deck surface in 1986 (1985 for the 3.0 MFI LN7). The change in the head bolt thread location was made the same time Torque To Yield head bolts and composite head gaskets were implemented.

The deeper threads move the threads away from the deck surface and minimize distortion caused by tightening the bolts. That combined with the composite gasket equalled a better head gasket seal!!

Stage 1 and 2 blocks are a complete different story.

 

[TheNovaMan]

Wouldn't head studs also reduce distortion?