1966 with turbo 400

[65truckowner]

I am planning on installing a turbo 400 in my 66 I am restoring. Has anyone rebuilt one of these transmissions? I can do about anything as far as engines and standard transmissions or transfer cases or rear ends but have never tried to build an auto. Is it something I should try?

[PGSigns]

Get a book on doing them and see if you feel comfortable with it and have the tools needed. If your truck is low hump you nay find the 400 is a bit tight. and may require some floor work. For a non OD trans I like a 350 better with the lower mass to have to spin up and he lower first gear. Everything I have done for the last several builds has been a 700. the OD and lock up sure is nice.
Jimmy

[65truckowner]

The original cross member has been removed will this help with it fitting?

[PGSigns]

No the 400 is just much taller than the three speed or the turbo 350 and you run out of room where the hum turns up at the beginning of the firewall. The high hump trucks have about 2 1/2" more space. Putting the 700 in my 65 with the low hump and a lokar shifter had it almost hard against the floor. Had to work the seam at the front of the hump pretty hard. Same setup in the 66 with the high hump went in like a dream in comparison.
Jimmy

[morethanstock66]

If you were a little closer to the DFW metroplex, I would say I have a turbo 400 in my 66 that has been recently rebuilt. Looking to swap for a stick

[rideblue00]

my 66 came with a 400 and a low hump from the factory, no probs there

[PGSigns]

Is yours a C10?
Jimmy

[Robert Haas]

My 65 GMC was a factory powerglide truck, and the 400 did require a little massage work on the hump to get things happy.

[steveb64]

No problem with the TH400 and Cadillac 500 in my 64 low hump. I have about an inch from the floor to the trans mounted Lokar shifter brackets. I used an aftermarket trans crossmember that bolted right up and positioned the trans perfectly, it's a rectangular tube crossmember that one of the truck part vendors sells.
I have rebuilt my TH400 a couple times with great success using the Ron Sessions book. No special tools needed. Also did some of the easy mods he outlines in the book.
With the Cad 500 engine, I needed the more stout 400 to handle the torque. Would love to have the overdrive, probably a future upgrade I will tackle.

[rideblue00]

Yup c10

[rideblue00]

I should add that my 400 came from a 66 c20 with a low hump. Its in a 66 c10 now. Ive only seen 4 speeds come with a high hump.

[65truckowner]

I hope the 400 fits without too many problems, What about moving the engine forward a little?

[franken]

I'd wonder why a TH400 is the OP's choice. Sure they're bulletproof, but they use (more than a TH350 for example) power, and have no OD.

I prefer a manual trans, so I'm unenlightened...

[65truckowner]

I am building a 66 chevy truck and have the 400 in my parts pile. Half of you guys say it will need some floor work and the other half say it will fit with no problem. I guess I will have to test fit it and see. I have 3 3 speeds laying around also but the last truck I build most of the people that looked at it wanted a automatic, it was a 3 speed on the column.