[MPKind]

I'm looking into installing a 1-piece ('68 and up) HB on my '65 Catalina to replace the 2-piece Butler stock HB that may not be adequate for my 455. It has the correct matching '65 (non-A/C) pulley set with PS, 2 groove crank pulley. Has the '66 or 7 timing cover with the cast timing tab for the 2-piece 5.50" diameter HB. Very stock appearing. I've read several threads on this and it is complicated. There is an SFI 18.1 PRW 2-piece on the market, so that's my backup if everything has to be swapped. I'd rather not RnR the entire bracket and pulley setup to '68 and up, but I will have to switch to a '68 8-bolt Timing Cover at the very least for any 1-piece HB. I have several questions and observations about what I've researched so far.

1. Are most/all aftermarket one-piece HBs dimensionally the same as the Pontiac OE 1-piece? End of hub to pulley mounting face.

2. Anyone install the PRW 2442101 2-piece HB? They are made in China, but the company is out of CA I think. SFI rated.

3. My best comparison of 2-piece to 1-piece is that it puts pulley mounting face about 1/2" further forward. Am I close?

4. Ames sells a crank pulley (N459FJ - 68-70 PS w/o A/C) with a very small offset, that may be able to shift the belt grooves backward to compensate for the 1-piece HB shift forward. If the pic they published is the actual part, it looks promising. Definitely shorter than the '65 crank pulley offset. Only need to make up about 1/2".

5. 1968 Pontiac used the 8-bolt TC, but with a 1-piece HB. This was the only year the 8-bolt WP was paired with a 1-piece HB. WP was 4" and same as the 64-67. Was the '68 WP pulley offset unique to that year?

6. Some aftermarket HBs require 3-bolt Chevrolet style pulleys. Could a '66 and newer 396 pulley possibly work to preserve the pulley alignment with the others? The stock piece appears to have a small offset.

7. If I used matching '68 crank and WP pulleys with the 8-bolt WP (4"), how much would I have to shim the PS bracket and upper alternator bolt to align? Or would they line up with the PS and Alt?

8. Is it true that the same bracket set was used from '67 - '70? If so, this bracket set was with both the 2-piece and 1-piece HBs, which makes me think it the alternator and PS pump position were the same for several years including 65-66 and only pulleys were changed.

To me there must be a way to swap some of these parts with minimal other part swapping given the overlap between bracket design (6?-66, 67-70) HBs (59-67, 68-76), and WPs (64-68, 69) 4" only. How many different crank and WP designs with different offsets? I think 'ol Pinion can straighten this out.