been looking through the forums here and over at ls1tech about swapping a ls1/t56 into my 88gta. I was wondering if those who had done it thought it was worth the time/effort or if they would have built a tpi engine for the same money. My car is a daily driver and have a long commute, does mileage pick up any? I'm getting around 19 mpg now with 3.45 rear gears. I'm good at fabricating and can figure anything out but its kinda discouraging to look at the swap all at once now, it just seems like so much!! Is it something that comes together but you have to look at one thing at a time like fuel, wiring and so on....Is it something that can be done and up and running in a week or so? Like i said its a daily driver and cant be down for very long!! The little things worry me, like the wiring and fuel system. To me the l98 is a dead end, n/a you can get into the 13s and be good mannered but beyond that you are going to make sacrifices. And on top of that my car has 275k on it and I'm sure of condition of engine/tranny. I would like input from lt1 swappers as well, how to handle all there is to do and time involved!!!

 

If it's a daily driver, and can't be down for very long, go with the LT1/T56. It's a Gen 2 block, uses the same mounts as a Gen 1 SBC, a little modification to the k-member but that doesn't hurt anything. You can mod the fool out of them, they love the juice, you can run mid-grade (89) octane gas in them, and I was getting 27mpg with the 3.42 gears, and currently getting 22 with a bad O2 sensor and 3.70's.

The LS1 is a nicer engine, but the car will be down longer, you will end up spending more money on the swap for exhaust where a set of 3rd gen headers will bolt directly up to the LT1 and the wiring is easier, TPI fuel pump will work and no modification to the fuel system is needed.

I love my LT1 and it's a great upgrade from the L98.

 

This might be a dumb question, but why not just swap on the lt1 intake and some better heads instead of the whole lt1 engine? That way you would skip swapping engines and not have that paperweight optispark. Dont know any better guys so dont smartass me that much with the replies!!!

 

You still have the batchfire injectors, running '80s technology for fuel injection and ignition. I don't know why people keep thinking that the opti is crap, it's not. The one in my car has over 143k miles on it and still goes good.

Plus I don't think you would ever get 25+mpg from a regular 350 without sequential port fuel injeciton.

 

I hate em cuz I had to keep replacing them on my brother and my car. His lasted 50k or so for each one and then take a dump. Mine was lucky to hit that. We used nothing but the gm replacements, no autozone specials and still had bad luck.

 

The main reason of failure on the opti's have been found that when alot of people are putting them on, they are forcing them using the bolts to pull them onto the cam and it's putting them in a bind causing failure. If you get a '95 model, they are pinned instead of splined so it's not as hard to get them put on. Also another thing that was pointed out was the guide pin in aftermarket cams alot of times aren't put to the correct depth which was also killing them putting them in a bind as well. Plus if you do alot of power washing of the motor, the non-vented opti's would die more quicker because moisture would build up inside causing failure.

 

Ok that makes sense. We both had 94's so we did have the splined ones I guess. Thats good info to know. We didnt do any powerwashing under the hood, I never have thought that was a good idea.

 

Seriously, posting the vote in this section of the boards is going to yield uneven results.

Everyone here is already doing the swap and beleive it to be the best choice.

I went with the LS1 just because it was a better design, you can get much more power with alot better gas milage.

 

I dont really care about the poll, was just playing with it since I'm new to posting. I know the ls1 would be nice but it takes quite a bit of time to swap and knowledge. I never touched and ls1 and thats what scares me. I would love to have one BUT I need to do this swap in a week or so, my car cannot be down any longer than that. I havent found a complete swap guide that tells everything I need (any good links?) to do this. The big thing that scares me is the wiring of it. I would love nothing more than to drop an ls1 in it but just dont have the knowledge. I would like to keep cost down on it and not go with a custom harness.

 

If time or money is an issue, then your not looking to do a LS1 swap.

 

Well that really wasnt a sharp response. If money is not an issue, why do people who do it ask what it costs? And many many cars that have done the swap are also daily drivers so I'm sure thats not as big as an issue as you seem to think. They are both concerns that should be looked into before doing the swap. If cost was no concern then you wouldnt see the threads on using stock manifolds instead of headers and making their own harnesses and not the custom harness from speartech or where ever. This is something that is very do able in a week with all the right parts.

 

loose mileage??? i had the L98 T56 swap and i was getting 26mpg.. in my 98 LS1 T56 i get 30.8 mpg.. you're not losing much


and i agree with StevenK.. time, money are a HUGE factor in doing this swap.. its the little things that nickle and dime you to death.

 

He was referring to building the L98, not keeping it stock, so there is a possibility of losing some MPG.

If you want to be able to get it done quickly, do an LT1, LS1 swaps have been known to take 3-6 months.

 

I dont see any reason why it should take that long unless no one is in a hurry to do it. Every swap I've seen isnt a daily driver so there is no hurry to it. If I parked mine all winter, I would be in no hurry either. Just what is it that makes it take so long?

 

Most opted for the tubular k-member, that would take some time to get, plus the tubular a-arms. Also some opted to get the Hawk's LT headers, and sent off their harness to Speartech to have it made up. I would estimate 4-6 weeks for all of that,

 

do u mean time from getting the engine to having it running or time the car is down because i know it will take a couple months to get all the parts together but i dont want the car down for that long

 

From the time the car is down.

 

How long is a car down with a lt1 swap? Why is it so much easier? LEss fab?

 

The LT1 is a Gen 2 SBC, it's based on the Gen 1 350 chevy. The clamshell mounts from a L98 car will work perfectly on an LT1 so you don't have to buy special motor mounts for the motor to work. Also you can put a T5, 700R4, 4L60E or T56 behind it no problems other than the tranny mount for the T56.

 

If you don't want it to be down long, just take it to Bruce Hawkins. It might take a while before he can fit your car in, but he can finish it fast after that.

Not counting the complete teardown for restoration/paint work, I think he had something like 50 hours into my car for actual engine/tranny swap and wiring, and that may have also included swapping the rear end IIRC.

Adam LaClair (tell him I recommended him if you talk to him)