I am looking for a double grove pulley with the number 9799128. Pulley is from a 69 -70 modle cars only I have changed the water pump to a later 11 bolt pump and need this to solve an alignment problem. I am also after the two upper brackets for the alternator from a 69 and later car. I know I can get these as repro but if someone has both pulley and brackets then I am happy to buy them and save on shipping.
Those brackets will need to be modified. They don't line up with the 11 bolt holes. Are you sure you need a 9799128? that is a 6.5" dia. The 9799127 is an 8" dia. Double check the pulley charts for 1968 and 1970. It changes with what accessories you have. I went through the same thing and it's a nightmare. Double check everything!
I have a 68 firebird 400 that I have just rebuilt the engine in. The timing cover and pump was heavily corroded and was advised to change to the 11 bolt pump from the 8. I believe the upper brackets from late 69 to 70? Cars would fit because they were all 11 bolt??? As for the pulley I have look all over the web and the best match for diameter to the 9788886 pulley was the 9799128. After measuring both 8 and 11 bolt timing case widths and to pump flange depths I realised there was a differents of about 7/8inch (22mm). Depth of 9788886 is: 1.875” Depth of 9799128 is:2.750”( from web) Differents of 7/8 (22mm) The pulley is from a 1970 car used the same crank pulleys as on the 68 (Pulley # 9790842 and 970843). All the information I gleamed from chart from: http://grandprixchapterofamerica.com/tech/pontiac-timing-covers-pulleys-acc-brackets/ Please if anyone thinks I am going the wrong way with this please tell me, I am only going off what I can find on the web. One other point I may be wrong but wouldn’t you water pump and fan be turning slower with a 8” pulley than 6 1/2?
I have a 68FB 400 w/ PS and an 11 bolt. I used a 9799127 water pump pulley, a 9790846 Crank pulley, and a 9786900 Power steering pulley. I also used Gates Power steering belt #7512 (51 5/8") Gates Alternator belt #7495 (50 3/32)
I agree, I'll stick with the long nose pump. The short nose one cost about twice as much anyway. Those 1970 pulleys must be extremely deep to have another 7/8" of depth than my 1966 pulley. Thank you so much for straightening this out for me. Doug
the 6062 series pulleys are for the short neck pump. You'd need to swap water pumps if you got that pulley. I'd stay with the long neck standard pump and find the 128 series pulley. Down the road you'll have a much easier time replacing your water pump if it's the standard long snout. The listings show it as 70 because the 69 listings only indicate the early short neck pump. There are TSB's instructing the service departments to replace the short neck pumps with the long necks and change out the pulley accordingly. Up to you but since you need to buy a pulley anyways, you may as well match it to the pump you have already which is the more readily available standard 70-78 pump.
I don't remember life before this site! I guess I remember getting a lot more done in my life besides pecking on a computer but I think I've worn out all my stories and knowledge on the locals and I always seem to learn something new here!
I installed the alternator for grins last night and it looks to be in line with the crankshaft pulley. I also mocked up a short snout pump that came in and as I suspected, the existing water pump pulley is still too far forward by 3/8".
"9799128 is the pulley number you want. 9799127 and 9799130 will work as well (different diameters, same depth)"
The tables in my book show the 9799128, 9799127 as 2 groove 1970 pulleys. For 1969, it shows the 2 groove pulley numbers 9796062, 9796061 & 9796060. I can't swear to the accuracy of those tables.
But I'll look for the 1970 pulleys and return the short snout pump. I should have gotten on this site before I decided to pull off my fresshly painted and installed long snout pump. Thank you, Doug
Yes, the late 69 and 70 pulley should solve your problem since you've got the standard long snout water pump. The 68 front strap on an 11 bolt timing cover issue isn't REALLY an issue, it'll work, it's just that you'll need to leave the bolt holding the strap to the water pump loose as you adjust the alternator because the front strap and the rear strap won't have the same arc for the alternator to swing through, think of it as a scissoring X with the center point where the alternator bolt goes through the two brackets into the alternator to adjust tension on the belt (it's not THAT far off but you get the point). Ah, you said you didn't even have the front strap so just buy the 69 strap and that will solve your problem there as well. Not the end of the world if you just run it with the back strap, other than having to put an eighth inch of washers to take up the space of the missing front strap, OR just twist in the back strap. It's definitely more solid with both but you can run it with just the back.
9799128 is the pulley number you want. 9799127 and 9799130 will work as well (different diameters, same depth)
Dennis, So if I understand correctly a pulley would solve the alignment issues but there would be a problem with the front adjusting arm of the alternator? Would I still need the short snout water pump in addition to the later 69 water pump pulley? Or the pulley you mentioned designed with more back spacing to accomodate the long snout pump?
I did not mention the alternator because at midnight I stopped mocking up and I "assumed" the alignment would be OK since it was before. My car has only had the rear alternator adjusting brace. And I did not know it was supposed to have two mounting arms until this past week when I was thumbing through some catalogs and drawings. Thank you for pointing out that there would be a problem with the front arm. Thank you for your help. Doug
I see you make no mention of the alternator or bracket for it. you'll find that the pivot bracket won't line up with that 11 bolt timing cover you have on there now. There is no depth difference between the 68 and back 8 bolt timing cover and the 69 and up 11 bolt cover in regards to the balancer. You've got two choices, one is to put the 68 8 bolt cover back on so your waterpump neck sits at the correct height and use the corresponding 68 water pump pulley -- that will give you the correct spacing to line up with the PS and alt. If you stay with the 11 bolt timing cover, you'll need a late 69 or 70 WP pulley but remember that the front alternator bracket will still not line up on the 11 bolt cover to match the back one since the bolts are in different locations. Not a big deal, but it will track at a different radius than the rear strap that bolts to the thermostat housing bolt. You can modify the bracket by cutting off about an inch, redrilling the hole, heating and bending the bracket into a tighter radius.
I can't recall the correct late 69/70 part number on the WP but I know it ends in "130"! The 128's and 129's are different diameter pulleys but at the same depth so you have a few to choose from.
I mocked up the water pump, A/C and Power steering last night. Using the book “How to Restore Your Pontiac GTO” I found I have the following part numbers.
Item - Part Number - Years - Comments Crankshaft Pulley - 9790843 YC - 1968–1970 - Single Groove Crankshaft Pulley - 9790842 YB - 1968-1970 - Two Groove Water Pump / Fan Pulley - 9782679 XJ - 1966 - Two Groove Power Steering Pulley - 9782671 XH - 1966 - Single Groove
The book did not specify what the part number should be for the A/C bracket on a 1966. I looked around some data plate decoding sites, and the A/C may not have been on the car originally.
With the long snout 4.5” water pump and the other components bolted on, there appears to be about 7/8” offset between the water pump pulley and the crank’s double pulley. The Crank’s rear single groove pulley is aligned well with the A/C pulley. The Power steering pulley is in alignment with front groove of the Crank’s double pulley.
So it appears that I will need the short water pump to make up some of the 7/8” offset unless the correct pulley for the ’69 waterpump has an exceptionally deep backspacing.
I am assuming that there may be two sets of ’69 water pump pulley since I have seen some listings for early ’69 water pumps (short) and the more common longer ’69 water pump. And Ames shows pulley sets for early and late ’69.
My book shows two different 69 water pump pulley’s, but they may be just different diameters. 9796062 - exc F/8 HT M40 less VP fan - 7 3/16” dia 979606 - F/8 HT M40 less VP fan - 6 ½” dia I am not sure what the F/8 HT M40 signifies. I think the VP stands for variable pitch fan. The book does not address the long and short style water pumps. Maybe the short style was only used on the 350 engines.
Does anyone know which if either pulley will work, or if one has more backspacing than the other? Do the late ’69 water pump pulleys have an exceptional amount of backspacing? My confusion is that the crank pulleys line up with the power steering and A/C pulleys, so it appears to be a water pump pulley problem. Or am I looking at finding a custom sized water pump pulley? Thank you, Doug
I'll have to check out the power steering more closely. I am not schooled enough on what pumps and brackets are original, but I'll see if I can find a part number on a pulley and dig into some books tonight. I believe the A/C is a 66, and I think the car was originally a Power Steering car.
I have a new 68 and up single balancer with 4 bolt holes. The old balancer was a 4 bolt one too. I tore into the engine because I noticed the crankshaft had fore/aft play of a 0.10", about ten times more than it should. Turns out the last rebuilder had put the #4 Bearing cap on the #1 main and half the thrust bearing was sitting on the outside of the engine.
This whole pulley alignment thing may explain why the engine was a mix of 68 timing cover with a 69 block. But the parts mixing does not stop there. It had a 70's Turbo 400, disc brakes up front, Ralley wheels, and a 67 his/hers shifter. It has been a challenge replacing parts. Doug
you've got a few issues but you'll need to clarify further, what power steering setup is on the car? was a later model swapped onto the car to create power steering from nothing, or is it an original 66 pump/bracket? there's a few combinations of pulleys/timing covers that work together but they all build from the PS setup. The 67/68 WP pulley will not line up on top of either version 69 pump. the early 69 pump is all by itself, the later model pump is the same height from late 69 up through 78. The early 69 pump has it's own height pulley to line up with 67-70 PS pump, the late model 69 Pump has it's own pulley to line up with the 67-70 PS pump. 71 and up setups will all work on the 11 bolt timing covers with 71 and up PS pump/brackets. A 68 pulley on top of either early or late 69 and up pump will not line up with anything (as you've found out) This is all pretty confusing but you need to establish which PS pump you're running. If it's the 66 pump and it's a 66 AC compressor, then you're going to have to go back to the 8 bolt timing cover or get a custom pulley made to sit on top of the 11 bolt pump. Do you still have the two piece harmonic balancer? the 67 and back where the two piece setups with 6 bolt holes on the pulleys. 68 and up went to a single balancer with 4 bolt holes.
As my handle suggests, my car is a Mutt. It is a 66 Lemans with power steering and A/C. When I bought it, it had a 69 400 block with a 68 timing cover. The old balancer was too big and had rubbed the tips off of the timing indicator scale on the timing cover.
I had the engine rebuilt and bought a 69 & up timing cover. I bought a new water pump and when bolting on the pulleys, I found that the fan pulley sticks out too far forward. I got online and started noticing that there were two water pumps for 69. One has a snout of about 4" and the other about 4.5". I have the longer snout pump. I am thinking of ordering the short snout pump, but I am not sure that will cure the offset. The pulleys appeared to be about 0.7" forward, and the short pump may only make up about 0.5" of that offset.
My question has to do with the pulleys. In a restoration book, I looked up the numbers on my pulleys and I apparently have a set of 69 crank pulleys and a 68 water pump pulley. Is there a difference in the back spacing or depth between a 68 water pump pulley and the 69 pulley? If the 69 has more back spacing or depth, it may line the belts up better.
I'm wondering if the reason the belts lined up before was because of the differences in the 68 and 69 timing covers and water pumps or is it a situation with different back spacing on the pulleys. Thank you, Doug
