[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.

[chiphead]

Lightning round:

1: Yes. If its listed as a pontiac balancer and has 4 bolts, its likely same as stock 68-newer dimensions

2: Don't know

3: Not sure about the pulley mounting face on the balancer. You'd have to compare the overall distance of the two balancers themselves.

4: Don't know.

5: I think the water pump pulley for '67, '68 and '69 with short 4" 11 bolt pump has the same offset. Diameters were different depending on AC or not.

6: Don't know. Very doubtful

7: The same alt/PS accy brackets were used for LeMans/GTO from '67-70. Not sure about big car.

8: Cast aluminum PS/ALT bracket is the same '67-70. Not sure about '65-66. or big car.

I went through this on my '67 Lemans/GTO. The 11 bolt water pump and 4 bolt balancer is worth the changeover. The '68 system still uses the 8 bolt pump, it sucks.
Run a '69 or '70 system for a GTO if that'll work in the big car. There is a short fan clutch that will position the fan in the correct place in the shroud.

[MPKind]

1. Good to know. Since the snouts on Pontiac cranks are the same, one could guess that no matter 6 bolt or 4 bolt the hub length is the same.

2. Seems like not many users of this part. Zero reviews anywhere.

3. It's all about the mounting face of the pulley. 6 bolt is about 1/2' thick and the 4 bolt is about 1" thick.

4. NO clue either, yet.

5. Need to get an accounting of the different crank pulleys used from 66 - 70 with offset dimensions.

6. 3 bolt HBs could allow for some crank pulley that aligns...no new info on that.

7. Using the matching '68 pulleys could work for crank to WP, but the alt and PS bracket would need to move forward. Maybe. Still not sure about this.

8. I don't think the pulley brackets for A or B body cars from 68 and up were different except for maybe F Body. Would need to see a parts catalog to confirm.

I'd like to find out what 'ol Pinion Head has to say about this. If anyone knows, he would.

[MPKind]

I could use some feedback on this...I know it's not that interesting.

[East]

I went around and around on power steering and alternator pulley alignment.

I bought an SFI damper from Butler, and removed the post '70 pulleys and used the correct ones that I had in order to line up all of the pulleys.

I had to buy the water pump pulley from Butler to retain the use of my current water pump. It is the 4 and 1/2 inch version.

I still have the balancer pulleys I removed, plus the 5 and 1/2 water pump pulley.

Thread:
https://forums.maxperformanceinc.com...d.php?t=868275

[chiphead]

Yeah, the '68 transitional system, followed up by the '69 short 11 bolt system really throws people for a loop. The accessory system changed every year from '67-71 so its a real PITA to straighten one out.

For the OP with the Catalina, I think changing to the '68 timing cover, 4 bolt balancer, 8 bolt pump and using the '68 crank pulleys would work with his factory brackets and '65 waterpump pulley.

For me, I was stuck with the '68 system for years because the 2 timing cover studs were in the top location and stuck in the block. Those are too short for the 11 bolt pump. Now I've got an engine with the 11 bolt pump, and man I'm never going back to 8 bolt. 11 bolt cools so much better, especially at low speeds.

[M91196]

Not super useful for the OP but for reference regarding 8 bolts, I wanted to keep the “proper” look for my 68 and made a Romac SFI balancer fit and used a Kaufman timing cover and his baffle and the cooling ability is plenty for my 11.5-1 Stroker

[MPKind]

Originally Posted by chiphead

For the OP with the Catalina, I think changing to the '68 timing cover, 4 bolt balancer, 8 bolt pump and using the '68 crank pulleys would work with his factory brackets and '65 waterpump pulley.

Agreed. I studied all the part number a design changes 64-70. The crank pulley POSITION relative to the block face was never moved. The pulley and accessory are a set that must match. The 71 and newer stuff appears more complicated if you try to mix and match different years.

[MPKind]

Here's a table showing the 64-70 pulley and parts combos for a 2 pulley system with P/S, no A/C. This mainly applies to Pontiac V8, but doesn't include the alternate parts sometimes used on A and F body cars.

The part numbers only tell part of the story, the design of the dampener and later the water pump is what revised the pulley positions. The overlap of designs, specifically 1968 indicates there are options to interchange up to 1970.