I am planning ahead for my upcoming 383 build and would like to make sure I have a clear plan ahead of me. The engine in question is going to be a 383 ci with under 500 HP but hoping to get around 400. I am planning to put it in an '85 T/A with a carburetor since I know a tpi system would be too restrictive. I have a 700r4 and disc break rear from an 87 and would like to know if they would hold up to the engine and what issues I would have putting the newer auto and rear in an 85.

Thanks

 

That rearend may last a while if you run only street tires. Slicks or DR's and it will be toast.
Unless your 700R4 is built by a very competent trans guy, it won't last long. Most trans shops don't do well building 700R4/4L60's. Where in Ohio are you located? There's a guy in Dayton who could build that trans to hold up.

 

I am just south of cleveland area in Ohio. The 700r4 is stock. I only plan to run on street tires for now, if I decide to start running the car I plan to upgrade everything at that point and probably more HP too. So if the rear lasts a while that'd be great for a fair weather cruiser.

 

Would the trans in its current form even hold up or will it need a rebuild to keep from becoming scrap?

 

Unless it's been built by a competent 700R4/4L60E builder, it won't last more than a few WOT runs. It needs line pressure modifications, because a given TPS with the stroker will put more torque into the trans than the same TPS with the stock engine. The 3-4 clutchpack will be the first to go.
It makes no sense to install it as is. You'll be pulling it out, rebuilding, and re-installing it shortly -- a big waste of time and money. Just get it rebuilt now and save yourself that grief.

 

As far as my personal skill level goes Ive rebuilt multiple engines from the ground up including in my DD Blazer. If I ordered the proper parts (providing recommendations of course) would I be able to rebuild the trans on my own or would I get in way over my head with it?

 

Get a kit and instructions from Dana here: www.700r4l60e.com

 

Would it be any benefit as far as durability to swap over to a TH350 instead? I haven't found a lot of good answers on whether the swap is beneficial or not over a 700R4

 

Since you have a 1987 trans, it's a decent foundation, so I'd stick with the 700R4 and the overdrive 4th for any car that's going to see road use, more than just getting it out for a cruise a couple of times a year.
IMO, a TH350 transplant would be primarily for strip use, and with all the ancillary modifications such as a new drive shaft, it wouldn't be cheap. Any TH350 trans you don't pay good money for will need a rebuild also.


My first recommendation is to get Mike Harris in Dayton to rebuild your 700R. If you want to go that way, I'll PM you his contact info.
2nd option: go with the rebuild kit from ProBuilt (link above) and do it yourself with Dana's instruction. You really need to have connections with a local trans shop and their tools to do this right though.

 

Okay thanks for the advice.

What issues should I be aware of putting the 87 700r4 into an 85?

 

bump

 

I would spend some time on you tube watch the 383 build by vintage iron

 

Thanks for the link, looks to be a good resource for the actual build to get a second opinion to compare to what my machine shop says. Luckily I have good people to do the precision machine work for me before I assemble everything.