A friend of mine has had some problems with the tired old TBI 5.7 in his 95 silverado. I have a LT1 sitting in my shop that he wants to swap in. His truck is a 4 wheel drive with 185,xxx miles and he occasionally takes it off road which brings me to my first question...

I've heard of the opti spark distributor being messed up by some people taking their LT1 trucks off road and getting it wet or muddy. Is this true? And if so, how can this be prevented? Maybe a simple splash guard?

One of my most important questions is with the transmission having 185,xxx on the clock, shouldn't a rebuild be almost necessary to handle the extra power of the LT1? This truck has a lift and 33inch tires which adds strain to the driveline.

Will the F-body accessories (a/c included) clear the frame without notching? Or is minor notching required to fit the a/c?

I have the wiring harness and computer from the donor car. Can the wiring harness be modified to work with this truck and keep all functions and gauges working or should I start from scratch with a custom harness?

Just double checking but the factory TBI v8 exhaust should work. Someone correct me if I'm wrong.

What will I need to do about the fuel system? Maybe add an external pump?

And any suggestions on what type of radiator to use since this is a reverse flow system? My dad did this swap in a s10 before and just bought a corvette or camaro radiator at advanced but this being a full size, I didn't know if there was a better option.

Sorry for all the questions but I just want to make sure I know what I'm getting myself into before I agree doing the swap and that my friend is satisfied with his truck after I'm done. If the total price of the swap is out of budget, then we may consider rebuilding the old TBI. I just figured that with the multi-port injection his truck might be a little more fuel efficient. Thanks

 

I have an LT1 in my 1979 Chevy. I converted mine to Carb so I can't answer your question about the gauges.

I considered using the factory computer but I was put off by the optispark issues. The optispark has a horrible reputation and the replacement parts are expensive. The MSD optispark is supposed to be good, but it's $500 bucks.

My LT1 was out of a caprice, and I did need to notch my frame to clear a pulley. I also removed the AC unit and replaced it with a AC delete bracket, and then I pulled that pulley off and bought a smaller one at Autozone so the frame notch didn't need to be as big. I then had to buy a different length belt (was also available at Autozone.

I know that isn't a lot of info, but that's what I have.


Dan

PS - the water outlets on the motor (Radiator hose outlets) are smaller in diameter than an older SBC. I used the caprice radiator so it wasn't a big deal.

 

You can do the LTCC (LT1-to-LS1 Coil Conversion) available from Full Throttle Speed. It still uses the factory optical module in the Optispark for reference, but no high voltage is passed through it. It uses the LS1 direct fire coils and eliminates the high voltage section of the Optispark. It also has a built-in adjustable rev limiter, a two-step rev limiter, and a built-in adjustable N2O & boost retard. The harness itself is plug and play; no splicing required. It uses 8 LS1 coil packs, which you will have to locate and then you will of course have to obtain a set of plug wires after you figure out where you want to mount the coils. You could either modify a set of factory LS coil brackets to mount to the LT1 valve-covers or purchase or build a coil pack relocation kit and remote mount the coils.

The kit costs somewhere around 400 bucks, but if I had an LT1 and was concerned with problems arising from the Optispark, which they are known to have, I would do the conversion.

 

i have a 97 z71 and want to go get away from that crappy vortec intake set up, and the only way to really improve that is to switch intakes completely, ive weighed everything and have decided to go with the LT1 set up as well, now im trying to make this a budget build as much as possible so im going cheap and keeping the same block, im going to get a pair of standard small block chevy heads and that will allow me to put the LT1 intake on that, now my friend thats going to be helping me is the tech guy so im just going off what he said but, if you want to get away from the opti spark set up, you can actually have the LT1 intake manifold sent off and machined so it will hold the distributor set up, thats my plan so id look into that