I recently was able to log back into my account by chance, so from now on I'll continue posting in this account instead of "Zs_JimmyBackup" Admins, I apologize as this was a mistake on my part. Now, onto the actual post.

So let me start off by saying I haven't been on this forum in ages. Ever since my former build got hauled away and hasn't been touched since, I've been focusing on life and other stuff before even thinking about touching my build. I've recently re-purchased one of my former vehicles, my 1996 GMC Jimmy SLE. It was my daily until I purchased my 2017 Mazda 3. Since that's my daily now, I've been toying with the idea of just throwing some junkyard 305 into it and using it as a not so serious project. It's a 2WD if that info helps.

Basically my question is what's the bare minimum to get the V8 swap "working"? I'm buying a dirt cheap TBI 305 that I'm converting to carb since 350's are going for gold near me and online right now and 5.3/6.0 LS motors ain't too far behind. I'm not looking to spend a ton of money, just enough to get the V8 Jimmy going. The 4.3 in it has over 230k miles and drinks oil like no one's business. So far from what I can tell I need to do the following:

- 305 Motor (Purchasing soon)
- TH350 Transmission (Have it at home)
- 2.8 frame mounts with 350 engine mounts (S10V8 seems like a decent site to get that)
- 2WD Shorty Headers
- Taurus e-fans
- Recess the radiator into the frame and ditch the AC compressor (AC hasn't worked in years anyways and this won't be a daily)
- Reuse my 4.3 accessories bolted on to the front of the 305 (new water pump due to reverse rotation on the 4.3)
- Custom driveshaft (I've gotten mixed answers on this. With the 4.3/4L60E I've been told a 305/TH350 would require a custom driveshaft. Not a big deal though)
- Fuel Pressure Regulator installed between the stock fuel lines and the carb itself
- Corvette Fuel Filter to allow for fuel return
- New TH350 Trans Crossmember (More mixed answers, some say the TH350 will sit in place of the 4L60E with little fabrication)
- Distributor/General power wiring
- Ford 8.8 Rear End (Later down the road once my current rear end goes out)

I know "search is your best friend" which I did a ton of way back when I was gearing up for this great 4x4 build. Problem is that was quite a few months ago and at this point I'd just rather know what I'm missing from this list to get it running. Once it's running I'll focus on buttoning up the rest of it down the road.

 

Seems like a lot of expense and trouble to swap in an engine that has less power than the original V6.


Is this a 4x4 build, or a 2WD build? You say both above


However, for 2WD


Original crossmember will work with TH350. Need for custom driveshaft depends on length of the TH350 (there are 3 lengths of tail shaft - short, long, extra long)


Stock fuel pump needs a return line type regulator. Relies of fuel flow to keep it cool.


2.8 frame mounts require you to remove the old 4.3 ones. Nuts for the bolts are on the inside of the frame and only accessible after you have removed the lower control arms.


Stock oil pan will not clear the front crossmember when engine is sitting at the angle required for correct driveline angles. This will be in the upper holes of the swap engine mounts (grind off the lower part). Use aftermarket pan and oil pump pickup designed for the swap. Milodon has one. If you try to leave engine in bottom holes of the swap mounts (front of engine raised), header flanges will hit on the firewall. Try to move the engine forward when in the bottom holes, the stock oil pan will prevent movement.

 

Sorry about that, my original build was for a 4x4 but this new donor is a 2WD vehicle. So 2WD is the vehicle in question.

I had read about using a Corvette style fuel filter for the return, I'll update my original post to reflect that. Also not afraid to throw in a new oil pan if need be. I need to swing by my storage and check the tailshaft length of the actual TH350. It came out of a 1978 C10, I know that. Lol

 

If 350's werent going for upwards of $1200+ around here and 5.3/6.0 weren't in the same boat I would go that route. But down here in DFW everyone wants one of these motors. Plus from what I remember, throwing in an LS requires not only a full custom harness, but also notching the frame. Never been too keen on cutting into the frame, even for a C-notch for lowering. Personal preference I suppose. I can get a 305 for dirt cheap however, so it'll be a nice little "fun" build I guess.

 

If you run a carburetor you will have to swap fuel pumps or get the pressure way down. Factory fuel injection runs around 50-60psi and carbs need 10-15psi.
The reason you see people using the newer corvette filter is when they swap to a newer fuel injected engine with a returnless fuel system. The factory s10 fuel injection is a return type system. Thats why you see 2 fuel lines on the back of the intake manifold instead of just a feed line.

You might have to shorten the driveshaft a bit but you wont know until you get the engine and tranny installed and take some measurements.
Same for the transmission cross member. you might have to make some modification to it or just move it around and drill new mounting holes.

 

I may have to swap fuel pumps then, which I'm not afraid to drop the tank and fix that up. I've already had the tank dropped once before to buy a replacement fuel pump a few years back. I could imagine forcing the pressure down 40psi probably wouldn't be ideal at stops, might flood out at the regulator.

 

I would suggest removing or bypassing the pump in the tank and just using a holley blue pump with a regulator.

 

That's it! I remember having that part bookmarked. It's just been quite a few months since I had all my links together. Thanks for that!

 

something that might help you too, Transdapt makes swap kits for these that come with most of what you need for the older carb V8 swaps.
Make sure you get the correct headers for either straight plug or angle plug heads depending on the engine you get.

 

I've seen TransDapt's kits and they're kind of a mixed bag of reviews. I've seen some work great and other people get multiple bad runs at once. I can't imagine it would be too much work to just piece together something at the same cost if not a little cheaper.