[Harley]

The oppertunity exists to install a "built"
700R4 in my El Camino. Behind 600+ Hp BB with
3.73 12 bolt Posi, 26.0 tires. What will have to be modified for this installation?
I have cross members for both th350 or 400.
Drive shaft is for 350 presently. Car is only
used for street fight'in some strip. The overdrive would be nice for the trip to town
or track. What do you think.
Harley

 

[Kevin]

Piece of pie! Shorten the 350 driveshaft three inches and move back the crossmember acordingly by using a different set of frame holes. The TH-350 cooler lines should bolt right up. Unless already done you'll need an Impala-type tailshaft piece on the tranny to get the TH-type crossmember mount. The TVI cable must get bracketed with your throttle cable - TCI has the bracket. You'll have to decide on using a lockup convertor - if you do you'll need to add a conversion kit that'll supply the ground signal to the tranny during fourth gear engagement. TCI has a nice little unit for this as well. You're gonna love this tranny.

 

[jholp]

When I did mine the drive shaft needed to be shortened 2.5 inches, so measure first.

I used a new T-350 mount that bolted (2 bolts) right up to the 700R4.

Slide the cross member support back and match or drill the frame.

I did not have to change the yoke so check out your configuration.

John

 

[Wheels68]

I agree w/ JHolp. Measure first before shortening the driveshaft. The yoke from a TH350 will work w/ a 700R4. Make sure you leave enough room for the yoke to move on the splines. When I shortened my driveshaft I bottomed out the yoke and then slid it back 3/4in . Then measured for the driveshaft. The 700R4 is a good trans, but it may be at its limit behind a 600 HP Big Block. If you want OD you may want to look into a Gear Vendors OD which will bolt on the tailshaft of a TH400 or a 4L80E which is an electronic TH400 w/ Overdrive. Both are not cheap but will better handle the power of a built big block. The gear vendors unit also lets you split 1-2 and 2-3 gear with the overdrive so you get a 6 speed out of the TH400.