Hi guys this is my first post here. I have a 92 rs with 305 and 700r4 in it. I am want to pull the 305 and install a 2000 chevy astro 2wd 4.3L in its place. I already own both vehicles and have been planning this swap for awhile. I know the motor mount locations are different and I will have to change the fuel system to get up to the higher pressure I need and pretty much have that sorted out. I was wondering if anyone had any insight into other problems I will run into. I found conversions to 4.3 tbi engines but not the newer fuel injected v6. I can weld and am a mechanic by trade I also have access to a full machine shop at work. Before I get blasted by people about fuel mileage and power not as good as a v8. I will say I am doing this swap as a challenge to myself. If I wanted fuel mileage I would get a Honda civic which I already have one and I also have a 383 stroker engine sitting in the garage that I'm saving for another project just not this one. So any problems anyone knows of with this swap please let me know or cool suggestions as well.

 

Just because I want to see this done, 1993 c1500 frame mounts for a 4.3 place the motor almost in the right spot. It may be a quarter inch off. Its a flat plate that bolts to the k member. A tpi pump will feed it. Exhaust would have to be custom. You need a 4l60E. Has to be from a 98+. You also need a f body specific tail shaft housing for 98-02. That's as much as I know. Personally think the 4.3 will perform as well as our eras 5.0 tpi with better fuel mileage depending on gear ratio. Also use the 4.3 cooling hoses. Use your factory accessory brackets and components. Biggest thing will be wiring. The 411 pcm that came in 2001+ vans, cars, trucks works great BTW and probably has more support.

 

A TPI pump will not feed it. CPI vortect systems operate at 60psi like LSx engines. Luckily late 90's c/k 1500 pumps fit 3rd gen tanks directly and are the correct pressure

4.3's are identical to sbc's on the backside so any 4l60e 1pc or 2pc case will fit. LSx 4l60es will require a converter swap because of the extended stub

The harness/PCM is close to LSx, so build accordingly. I do believe using the newer 0411 PCM is a wiser choice for tuning reasons. It's little more than a repin

Build an L shaped bracket for the TA mount and skip the tail housing swap

 

I was under the assumption that the tpi pumps flowed the required 61 psi when regulated correctly? The aftermarket specs say 60-90 psi on autozone, Napa, etc websites.

 

TPI and lt1 pumps put out mid 40's, sometimes peaking early 50's

If they would supply the higher pressure, stock ls1 swaps would leave the factory pump. It simply can't keep up at the higher pressure

 

Well, I learned something. Thanks. Also off topic, thanks for your contributions in regards to engine swap wiring. I couldn't have completed my swap without stuff you've posted over the years.

Op, take note of what he says.

 

Thanks for the info guys I'm rebuilding my civics transmission now and then the teardown for this will begin. I was planning on using the Astros 4l60e as well including the entire harness. I also planned on pulling the in tank fuel pump and tear apart the tbi in tank fuel pump and installing the Astros in its place but that truck swap sounds even better. I will post pictures as the project progresses especially on stuff that I have to modify to make this work. I'm going to swap the cpfi spider to the later Mpfi the van only has 59k miles on it and the camaro is really rough with 160k on it but all fun cars have to start somewhere. On another note the camaro has 2.73 open diff does anyone have a decent idea what gears would suit this engine tranny car combo best the astro is turning 342 gears. This car is a toy so I was thinking 4.11 but I don't want to run out of top end either.

 

Just make sure the gear ratio is programmed in the computer.