To swap or not?

[garlicbreath]

Quick and short, 1971 blazer, 350, Th350, NP205, D60, 14B, 4.56's and 37's and 2 brand new CV shafts. I need a lower crawl ratio, so I was thinking 2 options, 203-205 doubler or swap in a 700r4-208. The latter being much cheaper. Pro's-con's?

 

[jekbrown]

i wouldn't go to a 208 unless it has a fixed yoke. Why not a 231/241?

j

 

[Emmettology 101]

Ya, if you're going to go the route of a 208, I'd find a 241 and put a SYE on it. Or go with the doubler.

 

[surpip]

Quick and short, 1971 blazer, 350, Th350, NP205, D60, 14B, 4.56's and 37's and 2 brand new CV shafts. I need a lower crawl ratio, so I was thinking 2 options, 203-205 doubler or swap in a 700r4-208. The latter being much cheaper. Pro's-con's?

Ok here is how i see it. You have a 350 now, not a super strong tranny, but its ok, for the ultimate beef, youd want th400+dubbler.
you already have a 205, but it might be the wrong input, give a call to northwestfab, or send them a pm thay can help you ut alot with this decision.

700r4 is the same or a little less stronger than your current tranny, depending who you talk to. they can be built to handle qutie a bit of abuse, dr. watson from ord has used one for along time., i dont know much about the 208 though, sorry other than alum case and chain drivin, both are weak.

 

[garlicbreath]

Reason I was thinking 208 is they are easy to find already hanging off the back of a 700r4. And 700r4 has lower first gear plus overdrive. But I agree about the slip yoke, I have never liked them. Does anyone make an SYE kit for a 208? To go with a doubler, I would have buy and have installed a new output shaft in my th350, plus the cost of the doubler kit, and a 203 rangebox.

 

[TorkDSR]

depending on your rear driveshaft angle, keep the slip yoke. with 37's you only need a few inches of lift. so the dangle angle shouldnt be too bad for the SY

 

[jekbrown]

Reason I was thinking 208 is they are easy to find already hanging off the back of a 700r4. And 700r4 has lower first gear plus overdrive. But I agree about the slip yoke, I have never liked them.

didn't they use 231s or 241s in later K5s? behind 700R4s?

j

 

[sweetk30]

Ok here is how i see it. You have a 350 now, not a super strong tranny, but its ok, for the ultimate beef, youd want th400+dubbler.

350 not strong? i run that in my old truck worked great . and all my friends run them. but yes 400 is nice and stronger. as for the 700 dont ask me about those junk boxes. if i want od i will get 4l80-e.

 

[camok5]

I run a 700r4 208 slip yoke cv combo with 14 bolt dana 60 and 35 inch tires, so far no problems and you would save yourself some cash. Its great for me but mine is also a daily driver and I love the over drive but if I had the money it would be 400 doubler combo.