campin1983

iTrader: (4)

Ok, so I've had a thread going in the engine swap section for a little while, and I think I've settled on either getting the 290hp crate 350, the HO version with vortec heads that gives 330hp, or a used/rebuilt that is similar. My goal is a very streetable car that will see little/no track time, but just has to deal with my lead foot. This also is not my daily driver. And while I'm going to save up and try to do this swap right, its going to have to be on a budget.

Currently my car has the 305 TBI motor in it, and the drivetrain is all original to my knowledge. I assume this means it has a 700R-4 with 2.73 gears in the rear end (please correct me if I'm wrong). Its all got about 167,000 miles on it, but everything still seems to be working fine, and the tranny shifts without any problems.

The question is, when I replace the motor, what should I do about the trans and rear end? If I do indeed have a 700R-4 (hope someone can verify that, or tell me how to) should I keep it in? I assume it'll need a rebuild at this mileage, even if its working fine. So should I rebuild it, or just replace it with a stage 1 or 2 from bowtie overdrive, or something like that? I know the 700r-4 is used on 350 applications, but will I need to make any mods to it or the rest of the drivetrain when I switch motors?

I'm also thinking a 700r-4 is the most sensible tranny for what I'm looking at. Am i wrong? And what should I do about the rear end? Thanks!

WIll36

iTrader: (12)

Yes your bird has a 700r4 in it. Yes you should definetly rebuild it while doing the engine swap, because I highly doubt it will last long behind a healthy motor with that many miles on it. I would do a stage 2 monster transmission rebuild kit personally. Also your going to want to beef up the rear and go with either a set of 3.42 or 3.73 gears and something along the lines of a zexel torsen posi unit. Also think about replacing the driveshaft before it frags and dents up the floor pan. I blew the original out of my 88 IROC with just a 305TPI.

campin1983

iTrader: (4)

Well I'm getting a parts car this weekend that had a 500hp motor in it before the trans turned to mush. I'm not sure how much of the driveline is left, but I'm hoping I can steal the rear end, if not the driveshaft off of it as well. I'll have to actually see what those are though.

Good to know I at least have the type of trans I need. I think I'm actually starting to get a reasonable idea of what to drop in this car once I get the $$

fusion116

Yeah. I agree with everyone else. I blew my 700R4 out. The motor was pretty stock. It will go up especially with a motor like that in front of it. I have a 350 turbo. Pretty good trans, just not as good with gas as the 700. You are gonna have a pretty nice ride man!