th400 upgrade or rebuild

draft_man · Member

th400 upgrade or rebuild

cdnpont · Canadian Poncho Superstar!

If you are putting some some good BB torque to it, the 400 is the best and cheapest choice to live imop. But you're then limited to a moderate rear end ratio if you actually want to highway the car. No lower than 3.23's.

Some will recommend the 200, but I'd do a nicely built, thought out and controlled 700 on a mild 350 with a street gear. It's an easy way to go. Cheers.

draft_man · Member

I don't understand what you mean by cotrolled

draft_man · Member

meant controlled haha

cdnpont · Canadian Poncho Superstar!

That ever so critical TV Cable done and adjusted correctly. Moderate shift kit installed?

draft_man · Member

thanks

draft_man · Member

yes it will have a mod shift kit for firm shift but its only a 327 in this big boat .Not a race car hahaha

cdnpont · Canadian Poncho Superstar!

Are you doing a 700 Dwayne? I think a well done mild shift kit can extend the transmissions life regardless of the power in front of it. Poorly executed the opposite can be true.

Let us see what you're up to.

draft_man · Member

I have a tyranny shop I used to deal with a lot and he said he will build the 400 for a good price and then previous trans worked ok. I am using this car for a driver and will probably do a frame off in the future as it is not pristine but I can drive and enjoy it now. Its the same as my old car I had in high school so I just love driving it. My plan will be to eventually change to the 700 r4

draft_man · Member

bet you don't know what a tyranny shop is haha have to slow down on the send button haha

GLHS60 · Poncho Master!

I've never used one but have heard the TCI constant pressure 700 R4 valve body is a great up grade.

Makes the TV cable a kickdown cable only, eliminating the TV pressure problems.

Anyone used one??

Thanks
Randy

Pontiacanada · A Poncho Legend!

draft_man wrote:
bet you don't know what a tyranny shop is haha have to slow down on the send button haha

biggrin Sounds like something out of Monty Python.

draft_man · Member

What 700r4 should a guy look for? What make and model of vehicle or does it matter? what yrs? I know it can not be electronic but I also thought I heard that the early models piled up if you accidently towed in OD.

4SPEED427 · A Poncho Legend!

Likely the best years to buy are 1992 and older. The early 80s ones were the worst. 1993 and up are electronic.

long stroke · Canadian Poncho Superstar!

I have a 400 T.H. in my 74 Caprice and have been thinking long and hard about putting a 700 in her for better gas mileage. So this whole topic i find interesting. I have no complaints with that sweet 400 T.H., i just want better gas mileage.

1965CS · Guru

Personally, I prefer the 700R4 for the change. It is a fairly easy conversion but mods are needed to make it fit your 65, specifically the frame supports for the trans mount will have to be altered.

4SPEED427 · A Poncho Legend!

Driveshaft length 400 to 700 is not the same, right?

1965CS · Guru

Carl Stevenson wrote:
Driveshaft length 400 to 700 is not the same, right?

Right, I forgot that it has to be shortened as well. I also learned a long time after, that the front yoke is longer for the 700. Splines are same a PG and 350 but not sure about the 400.