help please

I own a 1986 Chevy caprice with a 305 and 700r4 Trans and it's no good (the trans) am I able to put a 700r4 from a 1991 caprice also with a 305 in to my caprice?

A TH700-R4 will fit. Just measure the tailshaft housing length and count the splines. It's also likely that the '91 version will have a TSS in place of the speedo drive gear, but that can be exchanged.

Thanks for the info if the tailstock on mine is different length I need to switch them correct? (As long as splines match) and with the speed sensor I can switch with tail shaft correct?

The spline count MAY be different (of may not be). By the records I could find, the change to a higher spline count was in mid-1984, so you are probably O.K. in that regard. However, trucks are a different animal, so stick with a car trans.

If it is different, you can tear down the trans and replace the tailshaft or get a driveshaft / yoke to fit the spline.

If the '91 has a VSS as I suspect, it can be removed and the '86 speedo driven gear and carrier installed in its place using the '86 clamp and thimble. You will have to inspect the drive gear on the tailshaft to make sure it is compatible. Some had straight teeth or a reluctor wheel, and some had the plastic helical gear like your '86. You may have to swap those by pulling the 4 bolts and tailshaft housing.

http://www.thirdgen.org/forums/attachments/electronics/184988d1252354435-electronic-speedo-cable-speedo-lastscan.jpg

Thank You Very much super helpful

If i put a tubro 350 Trans in my 86 caprice I'll have to move the cross member and possibly shorten drive shaft how to I get the speedo to work

If i put a tubro 350 Trans in my 86 caprice I'll have to move the cross member and possibly shorten drive shaft how to I get the speedo to work

The TH700R4 mount location is only slightly off of where the TH350 mount location is - you can actually get the TH700R4 crossmember to work without any real modifications. The driveshaft will need to be LONGER if you have a TH700R4 now and want a TH350. A driveshaft for a car with a TH200C or TH2004R will be the proper length.

Having said that, you will be happier with a TH700R4 in that car, if for no other reason than the 3.06:1 ratio first gear.

I own a 1986 Chevy caprice with a 305 and 700r4 Trans and it's no good (the trans) am I able to put a 700r4 from a 1991 caprice also with a 305 in to my caprice?

305 CU with a thm350 tranny is not a good match . good for a smaller car like a camaro not a full sized sedan. 305 lacks torque. 350CU with the thm350 would be a better match more torque . stay with a repaired 700r4 with the 305.