Consistency
 

I know this isn't a bracket site but I also know this is where the info is. Question: 70 Pontiac Lemans,350 c.i. built similar to stock rules, is a powerglide or a turbo 350 more consistant ? Also,car came with a b.o.p. 10 bolt. Is this rear worth putting any money in, or should I go with a 12 bolt ? I'm planning on trying stock in the future so I don't want to spend money where it's not needed. Car is not tubbed and is still in the building stage.It's basically a street car now torn down and getting cleaned,painted and ready for the strip.

Steve

I would take a long hard look at where you are going with your project & build with parts that will suit your later needs. Some cars never came with a P/G & only a 3 speed is allowed in those classes. No sense spending double.
my .02 for what it's worth

Adger Smith

Thanks for the response Adger. I thought some of the 350 engine cars came with the powerglide. If I'm wrong let me know. Thanks

Steve,

As Adger said stay as close to stock as possible..I do think they came with T-350, and yes the T-350 is the way to go...I would leave the tubs STOCK, don't touch them..You can still get a 30X9"
radial slick in there on a 10 "rim,with the right off-set....They made two 10 bolt rears, 8.2 and 8.5..The 8.2 is not very strong, but the 8.5 is what I use in my firebird and can handle a 455ci motor if set-up with good parts.You do need to decide if this is a race car or a street car ???? Good Luck Dave...1033/stock( 350)

Both Adger and Dave are correct. It does't appear that a Powerglide was available in 1970. The classification guide does not indicate a difference in shipping weights for TH, usually a clue that the PG was available.

c

Dave:
Is the 8.5 rear a direct bolt in for this car? If so,what cars did they originally come in? I'll start looking for one.What should I expect to pay for a stock one? Thanks

A 70 is an 8.2 . if you can find a lemans a few years newer it will be a an 8.5. the chevelle should be the same thing too.

novamoation

Re: Consistency
 

The easiest way to spot a 8.5 10 bolt is; it has square corners on the bottom middle near the rear cover.

Re: Consistency
 

Sorry bud, but you stepped into one of my pet peeves.

Pontiac did not use a Powerglide transmission, ever. Neither did Buick or Oldsmobile.
They did use a planetary two- speed known as the Super Turbine 300 ,or the Jetaway, depending on the brand. The only thing that's the same as a PG, is the gear ratio (1.76 PG) . The BOP trans is a stronger unit than the PG in stock form, but it never had any aftermarket support.
Calling one of these 2- speed transmissions a Powerglide would be no more correct than calling it a Fordomatic or a Powerflite.

Now , for your question. Put a Turbo 200 3 speed in it and look for a Chevelle , Monte Carlo or 70 GTO 12 bolt in it in case you ever want to use a 4.33 ring and pinion.

Re: Consistency
 

68-72 12 bolt chevelle/70-72 monte carlo rears will be a bolt-in (bring checkbook)
64-67 chevelles are an 1.5" narrower(bring 2 checkbooks)...
if you are not going class racing,i'd stick a 9" in it.
it'll be cheaper in the long run...