Changing to an automatic transmission

[cgster]

I have a 67 shortbed, pretty much original with a 283 and manual 3 on the tree. I plan on keeping the engine but switching to an automatic transmission. Is there an automatic transmission that won't require a driveshaft alteration? Which auto transmission would be the easiest to switch to? Thanks

[gmc684x4]

You will have to check tranny lengths to the 3 speed manual in your truck
T350 t400 where offfered in our trucks
200r4 fits in place of a t350 if i rember right if beefed up a bit it can be tougher then a 700r4

700r4 and newer 4l60 and 4l80 etc will need drive shaft shortened and the e models will need an electric controler for them

[Tyler212]

If you follow through with this I'd be interested in buying the clutch pedal from you. Either the full assembly or just the pedal, springs, and retainer if you plan on keeping the brake components.

My truck was once a standard and I'm looking to swap back but in the many moves since I swapped over I seem to have lost my pedal...

[BRL]

I swapped out my 250 IL-6 with 3OTT for a 350/350 combination in my stepside and the driveshaft was an exact fit.

I removed the riveted in trans. crossmember up front and added one from a salvage yard 68 Suburban with a Turbo 400.

Trans. crossmember bolted right into the frame holes further back.

I still used the IL-6 engine frame mounts from the inline 6 for the V-8, so the engine sits way back to the firewall but the Turbo 350 trans. had a short tail on it and the driveshaft fit just right.

You probably would have V-8 mounts in the front frame location holes in the engine compartment, so I'm not sure if a long tail turbo 350 would make up the difference, but anyway my setup worked perfect and it was entirely by luck.

[old51sedan]

Originally Posted by cgster

I have a 67 shortbed, pretty much original with a 283 and manual 3 on the tree. I plan on keeping the engine but switching to an automatic transmission. Is there an automatic transmission that won't require a driveshaft alteration? Which auto transmission would be the easiest to switch to? Thanks

I have a 69 shorted with a 250/automatic from the factory. I just replaced the 250 with a 292 and installed a 200-4R automatic overdrive. All I did was move the transmission crossmember back to the last set of holes in the frame and drive shaft slid right back in and bolted up. I believe the 3 speed manual and the automatic are the same length.

[palallin]

'67 could come w/ a PowerGlide.

[cgster]

Originally Posted by palallin

'67 could come w/ a PowerGlide.

Would that be a direct swap without having to change to much?

[kwmech]

Just put in what you want. I don't know why everybody gets hung up on the driveshaft length. Spend a grand or more on swapping the trans but don't want to kick down a couple hundred bucks for a new balanced shaft.

[Andy4639]

My personal thought is if your doing this why not get the 200r and have over drive. The truck will run fine and high way speed will cruise like a late model.

[palallin]

I swapped the other way--PG to 3 Spd--but I can't remember anymore if we changed the driveshaft. I don't think we did.

[Daves70]

If I remember correctly ( I am getting older) the 3 speed, 4speed Saginaw, muncie 4 speed, powerglide,200r4 and the short tailstock th350 are all pretty close to the same length. The 700r4 is about 3 inches longer.

[Andy4639]

When I went from 3 speed on the column to 700-R4 I had to cut the drive shaft. Had to buy a cross member and mount for it. Used stock holes and drilled to further back for it.

[MARKDTN]

Originally Posted by Daves70

If I remember correctly ( I am getting older) the 3 speed, 4speed Saginaw, muncie 4 speed, powerglide,200r4 and the short tailstock th350 are all pretty close to the same length. The 700r4 is about 3 inches longer.

Yep. TH400 and 700R4 are the oddball lengths.