How do I get the bolts into...

Discussion in 'V-8 Buick Powered Regals' started by gs_jimmy, Nov 11, 2010.

  1. gs_jimmy

    gs_jimmy Well-Known Member

    Looks like the hunt is on for a complete 7.5 MC SS rear. The 3.73 gears will work, although a 3200 rpm cruize is gonna suck gas. From what I can tell, I could upgrade to a 28 spline axle from a GN 8.5, but still checking on that one. Then I would need to switch to the S-10 carrier.

    So the final question is what will fail? Is it going to be the pinion, or the axles?

  2. regal81455

    regal81455 Well-Known Member

    I had a 7.5 stocker in my 81 behind what Im gonna guess was a 400+hp 455 and it lasted till started my frame-off. It was in the car for 8 yrs+ with that motor. I wouldn't worry to much about it if your on a budget.
  3. Don Palumbo

    Don Palumbo Well-Known Member

    I wouldn't waste my time and money on the 7.5. You are just going to break it.. Keep looking for the 8.5 GN rear. Even if you have to buy a ring and pinion to get the gear you want.. In the long run it will be cheaper than replacing the 7.5 over and over...
    Look at the picture of my car on my avatar, 8.5 GN rear, 28x10.5 slicks, 20 pounds of boost launch, off the trans brake, 9.64 @ 140.11, Moser axles, Eaton posi, and a stock 3.42 ring and pinion.. stayed together for 8 seasons before I broke the spider gears, replaced it with a spool..
  4. regal81455

    regal81455 Well-Known Member


    Id change over to a GN 8.5 too ( as a matter of fact I did ) however, he's selling this car. I wouldn't put more money into it -- let someone else. The 7.5 will last long enough for someone else to tear it up. Mine was proof of that - I beat the hell out of that 7.5. Thats just my opinion though.
  5. gs_jimmy

    gs_jimmy Well-Known Member

    3.73 gears

    Did you keep the 26 spline axles? Remember this is a street car, limited use.
  6. regal81455

    regal81455 Well-Known Member

    Re: 3.73 gears

    Yep - it was completely stock. As long as your not pulling holeshots off a transbrake with slicks you'll be fine. The tires will spin long before you put any serious torque on the axles/gears. Again, just my opinion based on my personal experience.
  7. gs_jimmy

    gs_jimmy Well-Known Member

    Sounds correct to me. 3.73's & a 26.xx tall tire equals great burnouts! Just don't want a snapped axle shaft. I see that all that is needed to go to 28 spline is a set of spider gears and 28 spline axles from a GN/442. Maybe later if I go breaking stuff. The gear set is a freebe that I already have. The ring spacer is cheap. If need be I can have a buddy check my work (in the event that this thing howls).

    Now I just need a good set of mufflers.....
  8. Don Palumbo

    Don Palumbo Well-Known Member

    Didn't know he was selling car.. In that case yeah put the 7.5 in it let the next guy worry about it..
    My Son had a 82 S-10 P/U that we put a 350 in and we broke a axle on the street in front of the house on the 3rd burnout...with street tires.. We narrowed a 12 bolt from a Camaro and installed that before bolting slicks on the truck..LOL
  9. gs_jimmy

    gs_jimmy Well-Known Member

    Well I pulled the cover off the 7 5/8 rear I've been saving to verify exactly what gear set I have. The number is...... 10:41xxxxxxx or 4.10. I also counted the rotations of the pinion to the ring gear and got just over 4 turns.

    So if I'm reading everything correctly I should be able to do the following:

    1. tear down both axles
    2. swap the complete 4.10 ring, pinion & carrier
    3. insure the preload to the pinion is correct
    4. insure the wear pattern, pinion to ring gear is correct
    5. fill with lube

    6. enjoy the new found cajones this will have!

    BTW this is an open rear end.
  10. gs_jimmy

    gs_jimmy Well-Known Member

    Gear swap

    I was able to pull down the 4.10 rear end last night. Looks very clean inside and found evidence that someone had changed out the fluid at some point. Wear seems to be minimual, bearings look great (no gunk or burning).

    So I just printed off all of the torque specs, talked to my driveline guy, and bought the parts I need (-$30 bucks!). Now comes the fun part, later I will tear into the 2.41 rearend and get it ready. Just gonna drop those parts into the s10 rear and button the up.

    I'm hoping to have this done tonight and see what the effect on the launch is. I expect good old tire shreading torque. I also found a set of 28 spline GN axles, so I guess I'll put the s10 axles up on the H-body board.


  11. gs_jimmy

    gs_jimmy Well-Known Member

    The 4.10's are a success! Car loves the new torque multiplication. Now I just need a good tune. Right now I have a miss at low RPM, but have not changed out the cap & rotor (tonight). Also the timing is set at 4*, and I will be bumping it up to 8* and adding 5 gal of UL Premium to the tank.

    Also have a dirty fuel filter to take care of and a stuck thermostat. :shock:
  12. gs_jimmy

    gs_jimmy Well-Known Member

    OK, this was a fun build. BUT, I have no time to properly finish out the car. So I'm gonna tear it back down and either sell it or put it into long term storage.

    Still needs a windshield and some paint work done. Driveline is going back into the GS.

    I do have a 1972 GS455 engine core, with rebuilt heads that can go with the car, along with a rebuilder TH400. As I said, only the engine/trans is being pulled, new aluminum radiator & d-shaft are still with the car and it will sit on Buick Ralley wheels. $3200 Posting it in the for sale section.
  13. gs_jimmy

    gs_jimmy Well-Known Member

    WELL it's over. I'm pulling out the BBB/TH400 tonight. I'll be buiding a large box in my shop and putting the GN into it. Along with all of the Regal/GN stuff and of course some rat posion for the critters enjoyment.

    I'm going to build a Grand Camino out of my parts, possibly with a LS motor & turbo set-up (have the intercooler already). So I'll be on the look out for an 86/87 Camino tub in the So. WI area. Not driveline of front clip will be needed.

    GN tub will get posted next spring.
  14. johnwwjr

    johnwwjr Founders Club Member

    I had the luxury of having the front suspension completely out when I installed mine, so like others on here, I just painted, actually outlined, the frame pads where they met the frame. I used a bare 455 block and the 200 4R bolted together along with the properly placed trans mount to mark where the frame pads should be. I also made sure the block/frame were each perfectly level and the trans tail shaft aligned with the rear end yoke. I placed and clamped in the frame pads after marking where they had to go and drilled pilot hole through the frame pad holes then opened them up fully with the proper drill. I attached them by dropping the bolt in from the top and put the nut in from the open lower a-arm hole under the cross-member. The attached picture was taken after I bolted the frame pads in and was testing the fit. Regal81455's example of welding them in is an excellent alternative if you cannot bolt them in.

    Attached Files:

  15. gs_jimmy

    gs_jimmy Well-Known Member

    Motor & Trans are back in the GS! Took about an hour to finish the unbolting of the underside items, pull as a unit and spin the hoist around. Dropped in with no problems.

    Now I just need to bolt the assessories back on, and build that box for the GN. Think I'll drop the extra 455/TH400 into the cradle to free up more space in the shop. Just need to find homes for all my other junk!
  16. johnwwjr

    johnwwjr Founders Club Member

    I wasn't paying attention to the dates on the posts, I sent mine out then noticed that I was just a bit late with the reply..... Just got back from a dinner party and the Sam Adams Octoberfest was flowing freely from the tap. Anyhow, glad you got your motor/trans installed.

    I'm getting ready to re-mount the body to the frame and that will take me some doing as I have to work pretty much by myself.

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