Hey I have a THM 700 R4 in my 91 K5 Blazer ....Is this a good tranny ? It has overdrive as well... kinda new at this and just wondering if my stuff is rugged or not

yes its a good tranny, 87+ have the better cases and 88+ have the improved planataries as well so you are in good shape. The first year of the 700 (82?) went thru like 40 valve bodies and was plagued with problems up till about '87 when things got sorted out.

My 89 has a 180,000 miles on it with no problems but the tranny has been flushed every 50,000 miles.

I've gone through 4 of them in the last 18 months, but thats because JET (so called) performance transmissions keeps sending me crap trannys. :mad:

The original stock unit lasted a long time.