[MrOtis]

Hello Folks! I am new to this forum and have a couple of technical questions for folks much more knowledgeable then I! I have inherited a 1971 LeMans. It is a great car and I love the lines. It is in great shape but does not have an engine/trans. I happen to have a newly rebuilt 1967 Olds 425 w/Switch Pitch trans that I am wanting to swap in. I am on a tight budget. Is this swap possible? What problems would I be up against? Thanks for your input!

[will slow gto]

Welcome to the PY Forums! The short answer is yes, it is possible. The frame & engine cross-member of your 71 LeMans is no different than the frame of any 68-72 Cutlass but you would need to source Olds specific engine mount frame brackets and the corresponding steel/rubber motor mounts. It does get a little more complicated if your LeMans has air conditioning and power steering as a lot of those accessories have motor division specific brackets.

I'm not sure how the case length of the switch pitch differs from the short tailshaft Turbo 400 which would have been available in the 71 LeMans. You may need to drill a couple of extra holes in your frame rails so the transmission cross-member is in the proper location. There's a good chance whichever driveshaft you source will need to be modified since you're going with a non-stock application.

All that being said, I have to ask, are you particularly attached to that Olds 425? Most folks around here myself included would prefer to see the 425 in a Cutlass and Pontiac engine in your LeMans. Obviously, the car and engine are yours to do with as you see fit but if you have receipts for the engine rebuild you might be able to find a buyer for it and then invest the proceeds into a Pontiac V-8. Good luck whichever way you decide.

[Scarebird]

I had a 425 in my 66 442: very good over-square motor - revved well with all forged components from the factory. 67 is nice as it has the 39° lifter bank (my 66 motor had the 45° ) I would run it without a second thought, especially if money is tight.

[Sirrotica]

The switch pitch transmissions are short tailshaft T400s, I purchased a 67 Buick transmission and installed it directly into my 69 GTO. Only difference is the A body harness has only 1 terminal and the transmission has 2 spade connectors.. To use the switch pitch feature you need to do some extra wiring in an A body.

[vidguy]

What Sirrotica said. I ran one for years in my 67 GTO.

[MrOtis]

Thanks everyone for your help! It sounds pretty straight forward. In it goes!

[mrrat1]

Down the road if you build a Pontiac engine it will basically bolt right in. With correct mounts of course!

[stevep]

A full sized Olds transmission is not a short shaft and there is no speedometer drive gear in it as big Oldsmobile had their speedometers driven off of the left front wheel. You can add the drive gear and remove the plug from the case so it will accept the driven gear.

Any Buick, Olds or Cadillac THM 400 from 1965-1967 had Switch Pitch. The 1964-1967 Cadillac trans will only bolt to a Cadillac motor up to 1967.

[Sirrotica]

The Buick La Sabre transmission from a 67 I put in my 69 GTO was indeed a short tailshaft transmission. I put it in myself and I certainly know the difference between a short and a long tail 400. I also installed a Trans Go shift kit in it so I had the valve body out and the extra solenoid that activates the converter vane angle. I must have just been lucky and got the short version. The pan has an identifying raised heel depression and 3 dimples in it, which mine did. It also had the 2 wire electrical connector.

Some of the B body cars did come with a short tail SP transmissions from the digging I did on the internet. It says the bulk were long tail transmissions, mine however was a short tail.

From my experience the transmission was a short tail, I incorrectly assumed all were, however the 4 inch tailshaft extensions were the exception, and the bulk were 9 inch extensions. The speedometer drive in an Olds is plugged as has been noted, and more than likely has the 9 inch tailshaft housing.

As far as Olds, I never have used one so I can't say for sure.

Sorry for the screwup on the information, I was speaking from my own experience with a Buick Le Sabre transmission, which happened to be a short shaft.

If you look at the picture in my signature of the 69 GP dirt track car, the black flamed 69 GTO behind it was the car I put the SP transmission in, No modifications were required, just bolted right in.

[stevep]

Buick did not use a long tail 400 until 1969. Did you have to change your tail housing as the 64-67 Buick THM 400 used a smaller yoke.

[KO]

I have a long tail switch pitch 1967

[vidguy]

Mine is a 67 Olds short shaft Switch Pitch. I've never measured because it was not an issue when I swapped it years ago... But I think it is the same exact length as the original PS TH400 that was in the GTO originally . I just removed the OLDS trans a couple months ago from the GTO.

[Sirrotica]

Originally Posted by stevep

Buick did not use a long tail 400 until 1969. Did you have to change your tail housing as the 64-67 Buick THM 400 used a smaller yoke.

The yard I bought it from looked in the Hollander interchange book (remember those?) and it was a direct fit according to the book. It went right in my 69 GTO with no changes whatsoever, still had the 2 spade connector which I never hooked up to a switch to get the advantage of the SP converter.

My car had 4.33 gears in it, roller cam, headers, etc, it really didn't need more torque multiplication for a street car with L60 14 Daytona bias tires on it, so I never got serious about hooking it up. Years later I wished I had at least tried it just for grins and chuckles.