ScottNM Posted June 28, 2011 Share Posted June 28, 2011 So, I have not found this debate thus far. How tough are the 10 bolt units that came in 1st gens? If a person has 500hp, will a 10 bolt handle it? I understand the early 10 bolts may be pretty stout. Is a 12 bolt unit substantially better? What say ye? Quote Link to comment Share on other sites More sharing options...
Mike 57 Posted June 29, 2011 Share Posted June 29, 2011 what 10 bolt do you have? Quote Link to comment Share on other sites More sharing options...
cny first gen 71 Posted June 29, 2011 Share Posted June 29, 2011 Oh wow that shot came out great Mike, both Mikes that is great picture and great launch Quote Link to comment Share on other sites More sharing options...
ScottNM Posted June 29, 2011 Author Share Posted June 29, 2011 I assume it is the "corporate" 10 bolt that most units went to in 72, I believe. The car has not been delivered yet, so I do not know all the details. I have a 70 with a 12 bolt. I will switch them out if that is needed. Quote Link to comment Share on other sites More sharing options...
Mike Brichta Posted June 29, 2011 Share Posted June 29, 2011 I don't race my cars but have spoken to more than one person who does race that says the 10-bolts are just as strong as the 12-bolts and are preferred because the axels are bolted in and don't have C-clips. Anyway, that's what I was told. Â Mike Quote Link to comment Share on other sites More sharing options...
Mike 57 Posted June 30, 2011 Share Posted June 30, 2011 I believe the BOP 10 bolt units did not have c clips they also had a larger diameter pinion shaft. The chevy 10 bolt had a smaller diameter pinion stem, C clips, and was weaker than the BOP units. Quote Link to comment Share on other sites More sharing options...
dbreese Posted June 30, 2011 Share Posted June 30, 2011 I had the stock 8.2 10 bolt c-clip style with and Eaton P-trac and Moser axles with 1/2" studs and a heavy duty rear cover. This was behind a fairly mild 385 that was not even close 500 hp. I made lots of passes down the 1320 and 60' times where in the mid 1.7 second range. It was always in the back of my mind that the rear would give up but it never failed. If you plan just street duty on street tires you can build the 10 bolt up and I think you will be ok. But if you take it to the track and put some sticky tires........It might spell trouble! Â With that being said I now have a Moser 12 bolt with bolt in Ford style Moser 33 spline axles and a Detroit Tru-Trac Posi unit. I also have a TA rear cover for added support for the carrier bearing caps. I do have a different engine now that makes a little more HP/TQ Â David Quote Link to comment Share on other sites More sharing options...
680HPStroker Posted June 30, 2011 Share Posted June 30, 2011 Street car 10 bolt. Street/Strip car 12 bolt with either weld on bearing housing ends(makes for a 9" Ford hybrid) that allows you to go without C-clips, or the cheap route is C-clip eliminators. I have the former rather than the later and with my setup wouldn't hesitate to send 1,000HP to the rearend. Quote Link to comment Share on other sites More sharing options...
ScottNM Posted July 13, 2011 Author Share Posted July 13, 2011 Just picked up my 72. It is a 350 4 brl with a 12 bolt. I guess I need to change the C clips to handle 500 hp ? Quote Link to comment Share on other sites More sharing options...
502ci Posted July 13, 2011 Share Posted July 13, 2011 Just picked up my 72. It is a 350 4 brl with a 12 bolt. I guess I need to change the C clips to handle 500 hp ? You could or at the very least get stronger C-clips axles, that's what I did. I have been running Moser C-clip axles for quite a few years now with many drag strip passes. My motor is putting out a little over 500 horses. Quote Link to comment Share on other sites More sharing options...
ScottNM Posted July 13, 2011 Author Share Posted July 13, 2011 Just found out it is 12 bolt but not posi traction. Why even have a 12 bolt. Now what Quote Link to comment Share on other sites More sharing options...
ScottNM Posted July 15, 2011 Author Share Posted July 15, 2011 It looks like 500.00 for the posi carrier to be installed. A 3:08 gear is 150 and bearings set is 100 and labor is 350.00. It comes to around 1100.00 for the conversion. How does that sound? Quote Link to comment Share on other sites More sharing options...
Ian Posted July 15, 2011 Share Posted July 15, 2011 That is about what I spent when I did mine. I went with a Eaton Posi, Motive 3.42 gears, and a strange crush collar eliminator.. Quote Link to comment Share on other sites More sharing options...
ScottNM Posted July 15, 2011 Author Share Posted July 15, 2011 How is that 3.43 gear working out? How is it for crusing at say 60mph? Quote Link to comment Share on other sites More sharing options...
Ian Posted July 15, 2011 Share Posted July 15, 2011 It is not too bad, but I am going to put a 700R4 in it one of these days. I do not drive it much so gas is not a big deal It really woke it up though. Quote Link to comment Share on other sites More sharing options...
CrazyDavey Posted July 16, 2011 Share Posted July 16, 2011 3:42's are great, you wanna wake it up...put those in... Quote Link to comment Share on other sites More sharing options...
ScottNM Posted July 16, 2011 Author Share Posted July 16, 2011 I think a 468ci 500hp unit with ATI torque converter and posi 308 should be a great combo for street/crusing? It seems like 3.08 is a nice balance. I drive open highway alot here in NM. The speed limit is 75 on I 40 and 65 on I25. 3.42 sure would be fun in town. Quote Link to comment Share on other sites More sharing options...
monteman427 Posted August 19, 2011 Share Posted August 19, 2011 I believe all gm 10 and 12 bolts are c-clip rear ends, and the big 10's have 8.8" ring gears and the 12 bolts have I believe a 8 and 7/8" ring gear and the bigger the ring gear the stronger the rear...jmo I have a 12 bolt with c-clip elimator kit , strange axles (35 spline) strange spool and richmond 488 gears and have never had 1 problem out of it and I beat the crap out of mine on a regular basis... hope this helps..Lee Quote Link to comment Share on other sites More sharing options...
Mike 57 Posted August 20, 2011 Share Posted August 20, 2011 From 68 to 70 Olds made a rear with a 12 bolt cover it had a 10 bolt 8.5 ring gear with the axles retained at the bearing. I do not believe that any parts interchange with other rears. I believe that someone had posted pictures of one they had picked up. GM seems to like to throw a monkey wrench into what you think you may be finding. Quote Link to comment Share on other sites More sharing options...
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