Im getting ready for a fall L03 to LT1 swap. I have few question I can not find the answer too. and... yes i used the search feature.


I have a 91 Firebird Convertible 5.0 TBI - my goal is to do this with the least mount of headaches possible.

1. What year LT1 should i go with? I was figuring 95 because of the MAF, plus the early Optispark distrubutor had durability problems that was revised in 1995 on the Y and F-Bodies.

2. 95 means also going with a 4L60E. Is it going to be a real pain in the *** to get the speedo to work? Especially if i plan on swapping to 3:73 or 3:43 gears in the rear...

3. Will all the gauges work?

4. Is the exhaust tough to get? Id like to go shorties to 3" y pipe all the way back to a flowmaster duel 2.5" inch outlets.

5. Can I keep the 700 tranny? What year LT1 and computer would I need?

6. Cooling system?

7. Difference between LT1 from F body and the Vette?



Thanks for any input

 

year 96-97 had an OBDII computer, and LT1s before that have OBDI. Most people seen to prefer OBDI since it is easier to tune compared to the OBDII.But if your sending it off anyway I guess it shouldnt matter. And most f-body LTx's came with aluminum heads, and B-bodys came with steel heads

Stock guages will work

I have a Magnaflow cat-back, and love it. As for headers, if your looking for a direct bolt up, get hedman shorties and they also sell a y-pipe that will bolt to your stock exhaust.
(btw, dont pay the $500 retail for an exhaust, look for one used with low miles. you can use the leftover cash for headers!)

You can use your stock radiator, Or 4th gen radiator.

Diffrence is Vette has a 4-bolt main, compared to the 2-bolt in f-bodys. Plus accesories on the Vette are different.

My advice, find a donor car with everthing you need. saves coin and time in the long run.

hope this helps.

 

2. 4L60E is actually a less of a pain to work with the LT1. The electric speedo on a LT1 setup is powered by the PCM. The PCM reads the speedo sensor and calculates the speed based on what gears are programmed into the PCM. When you want to change gear ratios in the rear, all that has to be done to get the right speedo output is re-program the pcm instead of changing the speedo gears like on a 700R4 setup. Also the 4L60E does not have a TV cable like a 700R4. Not all 4L60E's are interchangeable unless you change out some internal parts in the tranny. 94's are not interchangeable with any other year, 95's are not either, 96 and 97's interchange with each other.

5. 700R4 can work but need to install a TCI lockup kit, 4L60E speed sensor, 4L60E reluctor, 93 TV Cable bracket, 93 throttle body. I've done this before and prefer just going with a 4L60E.

6a. As stated above, 4th gen rad or 3rd gen radiator can be used. A lot of people prefer the 4th gen rad because the 4th gen LT1 dual fans can be used then.
6b. For A/C, I am the only one who makes A/C retrofit kits for the F/B/D-Body LT1 in a 82-92 f-body. At the moment, the only issue with my A/C kits is that they do not work with certain headers as the a/c lines run into certain headers.

 

the programming of the speedo requires a tuner? or am i able to do that with like a snap on solus?