[taff2]

IMO, you can't beat the early 389 blocks . '58 to '60 are the best but are probably a bit limited on bore size . If you want a smaller cube engine the 2 bolt block can be fitted with splayed 4 bolt caps and they are very thick in almost all dimensions going by the one I sonic'd. I also have a '61 389 block to use in my next n/a build,although this doesn't have the lengthways stiffening rib that the '58 to '60 blocks do, it is also very thick dimensionally and has the 1/4" taller main caps too. Although these blocks need an adapter to fit them to a TH400 pattern gearbox, this isn't too difficult to make. Now if someone could start manufacturing these adapters cheaply in 1/4" steel........ (The ali Wilcap adapters are a bit thick for my liking and quite pricey too)
Thanks go to Steve Barcak for bringing the virtues of these early blocks to the attention of the Pontiac world.

[LMSRACER]

Originally Posted by taff2

IMO, you can't beat the early 389 blocks . '58 to '60 are the best but are probably a bit limited on bore size . If you want a smaller cube engine the 2 bolt block can be fitted with splayed 4 bolt caps and they are very thick in almost all dimensions going by the one I sonic'd. I also have a '61 389 block to use in my next n/a build,although this doesn't have the lengthways stiffening rib that the '58 to '60 blocks do, it is also very thick dimensionally and has the 1/4" taller main caps too. Although these blocks need an adapter to fit them to a TH400 pattern gearbox, this isn't too difficult to make. Now if someone could start manufacturing these adapters cheaply in 1/4" steel........ (The ali Wilcap adapters are a bit thick for my liking and quite pricey too)
Thanks go to Steve Barcak for bringing the virtues of these early blocks to the attention of the Pontiac world.

taff2,
I agree with All of that. As you have mentioned, the Bore Size is the limiting factor. IMO, for a Racing Application, I don't want a Bore Size any Smaller than 4.185". I prefer 4.210" or Larger.
Therefore I believe that the trouble associated with the Early 389 Blocks just isn't worth it. That's My ...
On the other hand, the CV-1 Cylinder Head with the Correct Ports could change all of that. The Bore Size would be less of a factor, for sure........ The Jury is Still Out on that one.

Larry S.