[marks73ta]

I think Pontiac recast the 301T with the lighter 400 (77-78) measurements. The early standard 301s were paper thin in the webs etc. The 301T is not as thick as the '68 to '76 400 blocks. The '80 301T block I had also used drift pins instead of solid cap dowels and the pin/dowel holes were drilled all the way thru. The center three drift pins could be punched all the way thru the back (top) of the main web. I always felt that the added beef of the T block would stand up to a good short stroke combination better than a small block chevy would. Plus th esmaller bore would mean lighter pistons. I had the block with intentions of building a strong short stroke short deck Pontiac. Due to the several differences I gave up. I did buy two sets of Callies 6.2 length/1.88 Honda rod journal rods from a Nascar team that had changed engine configurations . I'm still setting on them just in case I can still do one. My intentions were to have a custom crank made. 3.25 stroke, Honda jounals, but the 3 inch mains. At one time I had two 370 3.56 inch stroke forged cranks for this project. They use a 2.63 main journal. I had a set of spacers made but never finished them to use those cranks but I was always put off by the unavailablity of good main bearings for this size. I had bought a set of bearings from EGGE but they could never provide me with the manufacturer of or the material from which the bearings were made. Many times their parts are NOS found on shelves somewhere so they did not know. Even with the spacers and trusted bearings I still had the problem of solving a rear main seal. The 301T using 3 inch mains/seal machined channels and the 370 using the 2.63 seal diameter. I never got close to figuring out what to do there. Hence the custom crank with the 3 inch mains. Next is the lifters. Not sure what lifter will work there. Never got that far. The thrust bearing width consideration was next but like Tom said, I think a shimed 400 bearing would work fine. The next consideration is the short deck water holes. They are cast odd size/shaped openings compared to the the machined holes in the decks of the full size Pontiac blocks. I also never got to the point where I could figure out if that would present a problem or if it was easily fixed.
Skip. The gentleman down here in Phoenix running the NHRA stocker Turbo Formula is Rick Unterseh. The block I was talking about went to him after he blew his last motor. I don't know for sure if he ever used it as he was talking about giving up on racing the Turbo anymore. The motor he blew was a really intense build intended for Stock class and he was pretty down when it blew. I haven't talked to him in a long while. Mark L