powerglide needs to go ! can i get some opinions for a replacement .

[250powerglide]

hmm sounds tempting but me being ignorant in this dept i may be better finding a vehicle so that i can get the brackets and cables ?

[72freak]

Originally Posted by 250powerglide

from what i understand the 350 wont fix my problem as far as high rpms. !

This is correct!!! You will need a 700 or 200 or a gear vendors overdrive unit.

[Palf70Step]

If I remember correctly, since you's is a 69 and with a T350 or 200-4R, you'll need to convert your throttle from a rode to a cable assemble for the linkages to work. Stock wise, the linkages are pretty plentiful for the V8s, not so for the 6's. But I am sure Loklar has one that will work. This is one of the reasons I went to a 350 in mine instead of staying with the 6 (although I wonder now at times if I should have stayed with the 250)

[dyrt]

My vote is a 700r4 or 200r4. They will both need a tv cable setup and a cable pedal, but the 700 will need a shortened driveshaft. There is really no EASY way to upgrade to OD since all of the transmissions need some changes to be made in order for them to work. If you are not hauling anything seriously heavy then either will be fine, especially when you are just cruising. Both of these transmission came in gm wagons and the 700 came in the suburban, so you know they can haul the weight of one of our trucks and a few people just fine. If i had to choose i would pick the 700 since they are more plentiful and came from the factory rated for more power. It also has a lower first gear for better takeoff. from what have gathered, you can use the factory auto crossmember, you just need to slide it to the right position for the rear mount and drill new holes in the frame.

http://www.maliburacing.com/auto_tranny_id.htm

Here is some info for gearing and trans dimensions. I would expect to put a few dollars into the conversion. I know inline 6s came in chevy 1 ton trucks into the late 80s, but i don't think they came with overdrive automatics so i doubt those throttle brackets will have a provision for a tv cable, but i am sure someone figured this out by now.

Mike

[250powerglide]

Originally Posted by Palf70Step

If I remember correctly, since you's is a 69 and with a T350 or 200-4R, you'll need to convert your throttle from a rode to a cable assemble for the linkages to work. Stock wise, the linkages are pretty plentiful for the V8s, not so for the 6's. But I am sure Loklar has one that will work. This is one of the reasons I went to a 350 in mine instead of staying with the 6 (although I wonder now at times if I should have stayed with the 250)

if my truck had come with a 350 i would have been happy . but after looking on the board and learning all of the cool things that can be done to the i6's it definatly has a cool factor being that it isnt as common as the 350 . actualy i wish it had come with a 292 !

[sierra4x4]

One thing to watch out for is what intake manifold you have. Not all had the hole drilled for the cable throttle or cable kickdown. If yous is not drilled then I would suggest going with a th350 with the kickdown cable not hooked up. If you do have the drilled manifold then I would switch to a cable operated throttle and get a 2004r trans. The overdrive 2004r will still take a little bracket fabrication but it its simple. The photo shows what hole I'm talking about. The second photo shows a stock 250 with a th350 and a cable throttle like you would need for proper th350 kickdown or slightly modify it for 2004r TV cable operation..

[Indyuke]

Thy quandary you're in is getting the proper ratio of launch power to highway cruising rpms.
- The powerglide with hi rear (3.73 or greater) gearing has good launch power, but poor highway cruising. On the other hand the pg with 3.07 rear is an ok compromise between the two. Somewhat sluggish launch and fairly good cruise. Good rpms at 50mph, awful rpms at 70. 1:1 final drive ratio.
- The t350 and t400 is better... you get great launch with hi gearing, but again poor cruising rpms. With 3.07 gearing you get pretty good launch and fairly good cruise. Also 1:1 final drive.
- 200 or 700r4 is best. The 700 will give you excellent launch because it's first gear is something like 1:3.06 vs 1:2.52 for the t350. Good n torquey. And with a final drive of about 1:73 you'll get good highway rpms. Because of the OD, you won't want to run rear gearing of anything less than 3.73.

I've got a 350, 700r4 and 3.73 rear gearing combo. It works pretty well, however I'm looking to go to the stock 250 I6, T350 with 3.07 rear. I've driven many trucks with that combo and for some reason I like it much better. Seems simpler and I don't have to deal with the 700r4 first gear being so low.