stage I & II differences

[49-blues]

What are some of the differences besides the 6 bolts for the heads? any difference in the strengths of the different blocks?

 

[turbodave231]

The Stage 1 and Stage 2 (offcenter) use the exact same raw castings. The Stage 1 was machined just like a production block and had cast iron 2 bolt main caps. The stage 2's were machined with the oil galleries just outboard of the lifters so the lifter could be left dry.

The lower half of the Stage 2 block was machined for 4 bolt center caps, and the boss at #1 main was machined to accept the oil pump pickup.

There was never an On-center version of a stage 1 block to the best of my knowledge.

A Stage 1 block is a very strong piece. Much better than any 109 block. If you were to add 4 bolt center caps and bush the lifter galleries, the stage 1 block would become a stage 2 block (with a couple of oiling differences)

 

[jevansengr]

Stage I to Stage II Block

And drill the top of the block for the 6 bolt heads.