TH350 to 700r4 swap

[87Skier]

Well, because I can't just leave my stuff alone and the engine feels pretty gutless from a stop I'm already planning on swapping in a 700r4 and changing out the front/rear diff.

I know its about 3" longer, so what have you guys done? Engine forward, or transfer case back? How did that work out?

[jaros44sr]

Originally Posted by 87Skier

Well, because I can't just leave my stuff alone and the engine feels pretty gutless from a stop I'm already planning on swapping in a 700r4 and changing out the front/rear diff.

I know its about 3" longer, so what have you guys done? Engine forward, or transfer case back? How did that work out?

Engine forward is the best, no fooling with the driveshaft lenghts

[warbucket]

I'm with Jim, I moved the engine 2" forward then used the Advanced Adapter 1 3/4" spacer to mate the 205. I relocated the transfer case support 1 3/4" back. I have a 2 1/2" lift and a 14 bolt rear and had to set the pinion angle so I moved the rear back 1" to center the wheel in the wheel well. I can still run the stock drive shafts but I set the pinion for a CV shaft from Tom Woods.

[elkniks]

Everytime someone calls your Blazer a Bronco, God kills a kitten.

HAAAAAAAAA! I really did laugh out loud when I read that. How many times have you looked at someone who just called your truck a Bronco and had to count to 10.

[IwantaK5]

Originally Posted by warbucket

I'm with Jim, I moved the engine 2" forward then used the Advanced Adapter 1 3/4" spacer to mate the 205. I relocated the transfer case support 1 3/4" back. I have a 2 1/2" lift and a 14 bolt rear and had to set the pinion angle so I moved the rear back 1" to center the wheel in the wheel well. I can still run the stock drive shafts but I set the pinion for a CV shaft from Tom Woods.

Is your trans a 700r4? I did the same trans swap and i didnt need any spacer. Just the proper output shaft from AA.

[warbucket]

yes, 700r4, the trans I had was already rebuilt and I didn't want to send it out to change the shaft so I took the cheaper option.

[87Skier]

That was going to be my next question! I have a broken 4L60E on my garage floor right now and the only difference I can spot in dimensions is the output shaft.

So I can pickup a shaft for a 700R4, put that in and will directly bolt in place of a TH350, or it still slightly longer? Either way, the engine will be going forward. Sure would be nice to actually be able get to the distributor.

[warbucket]

It will bolt in. With the spacer you have to trim the output shaft so it won't bottom out in the transfer case. I heard some guys had clearance issue's with the CV joint on the front driveshaft hitting the trans pan when using the AA shaft.

[JMac11]

We trimmed the shaft, no spacer. Just test fit to make sure splines are fully machined far enough back.

[87Skier]

Alright, I checked my splines in the transfer case adapter and it seems I need a 27 spline, so that's all good. I had considered trimming the shaft. Is the case of the 700r4 actually any longer? Or does the extra length come from the shaft?

[JMac11]

We still had to move the motor forward, unbolted cross member slid everything up

[87Skier]

I was thinking it was a little longer. How much longer is it actually? Just trying to get an idea of how close the engine will be.

[JMac11]

I could still run a fan, cannot say if it was the "right" Blazer fan or not. Same thing on fan shroud. Only hard part was loosening the exhaust clamps to let the engine move.

[tismy65]

will the transmission mounting support be the same as the 350

[87Skier]

Originally Posted by JMac11

I could still run a fan, cannot say if it was the "right" Blazer fan or not. Same thing on fan shroud. Only hard part was loosening the exhaust clamps to let the engine move.

I converted to an electric fan. So I'll need to hack up my fan shroud some more but no problem.

Someone correct me if I'm wrong here, but the 700r4 and TH350 both relied on the engine and transfer case as support. There are no actual mounts anywhere on the transmission case.