jfreeman74

I have read just about every LT1 swap post and article but would like to get some clarification of a few things. This engine that I am looking to use is out of a '95 Caprice with harness and ecm. I will be keeping my 700R4....

1) Will I have to use an ECM from a '93 or will the '95 work? Will I have to reprogram it?

2) I read that I would have to change to a '93 TB to be able to use the TV detent cable. Will I be able to use my stock cable?

3) What changes will have to be done to make the 700R4 work with the TC lockup? What about the VSS?

4) Will my instument cluster still work?

TexasLT1

1. '95 ECM should work fine

2. Stock cable should work

3. Not sure about that, not familiar with the 700. For the VSS, you have a cable speedo correct? Best bet is to get something like the Autometer aftermarket VSS that has a cable drive as well as an electronic output that will hook directly to the ECM. Check Jeg's or Summit, they both have it for about $65.

4. Yes

Z28ricer

iTrader: (2)

You will need a 93 Throttle cable bracket to go along with the throttle body.

As far as the VSS goes, the pulse rate between a 700R4 and the 4L60E is so different it isnt even funny, the 4th gen rate on a 6 speed alone is about 45 thousand pulse per mile, auto is just over double that, a 3rd gen is 4000 per mile, there is no plug and play sender that will work, what im about to attempt which *should* work is use the autometer 16 pulse / rev sender jegs sells, where the stock one is 4 pulse per rev, this will step it up some but not enough, not to mention the sender is a 3 wire type, then i'll be feeding that signal into a Dakota Digital SGI 5 to step it up to the correct pulse rate. We'll see how it works soon enough. For this to work you'd need your computer reprogrammed to the T56 input rate.

You will also need a TPI TV cable if you dont already have a tpi car since the TBI and Carb ones are shorter.


As far as your instrument cluster, if what im about to try works like its supposed to it would solve the problem of having to buy a Cable Xbox for the pre 90 camaros, and with a 90-92 the LT1 pcm has a 4k / mile output so provided it is fed the correct input it will work perfectly with a stock 3rd gen cluster, its a win win situation provided the sgi 5 and autometer sender work as they should.

You can buy a Convertor lockup kit from Jegs to control the TCC in 4th gear when it should work and it has a manual override option too. This is another item im using on this swap.

TexasLT1

You just said yourself the Autometer VSS is 16 pulses per rev. If you are going to use the SGI box you will want the 4L60E program in the computer. The T-56 program uses 17 pulses per rev, auto uses 40. Either use something like Tunercat to change the number of pulses the computer is looking for to 16, or use the SGI box to step it up to something like 32 and use the 4L60E program reset for that number of revs. It's pointless to get the Autometer sender, the SGI box to step it up to double or more, then use the T-56 input rate that is back at almost exactly what the Autometer VSS outputs.

Z28ricer

iTrader: (2)

Sure thing buddy, except for one little HUGE problem, the stock thirdgens have gears stepping the rate at which the speed sensor spins down, so at best you can get around 1/2 of the actual pulse rate, nowhere near the actual signal that the 4th gen produces being 17 per DRIVESHAFT revoloution, whereas the 16 pulse autometer will get you 4x what a stock one will being 16,000 per mile, but at 17 per driveshaft revoloution a 4th gen T56 with 3.42's and stock size tires is producing about 45,715 pulses per mile, just a hair bit more than that 16,000

On a side note I bolted the 700R4 to the engine that will be going in last night, the TPI TV cable is actually too long, seems like a TBI one is definetly too short, im going to try a V6 one soon, if that doesnt work it looks like a 92-93 LT1 TV cable will also be needed when doing the swap with a stock 700R4

therckid

texas, please dont argue man. This d00d has done countless LT1 swaps and knows his ****. YOur my dawg i just really dont want you to end up embarassing yourself in the long run.




Shane

pasky

Dude, seriously, shut your mouth, no one needs advice about arguments, this is a tech site and thats exactly what thier discussing.

TexasLT1

Yeah, thanks there bud.



jfreeman, obviously there is a difference of opinion here. If you want to spend the $65 for the Autometer sender, the $80 for the SGI-5, $50 or more for the computer reprogramming, then be my guest, it's your swap. But if you want to have the exact same VSS function for about $30, send me a PM and I'll show you how I did mine.


z28*****, after doing more indepth research into cable speedos, since I have never dealt with those, I now understand what you are saying. However, from what I've seen and by my calculations, the Autometer sender will still work without the SGI-5. All cable speedos operate at 1000 revolutions per mile, which, when figured in with the 16 pulses per revolution, obviously equates to 16000 pulses per mile. Now, we know the stock T-56 input rate is approx. 45,000 pulses per mile, or 17 pulses per driveshaft revolution, therefore the Autometer sender works out to about 6 pulses per driveshaft revolution; well within the range allowable in Tunercat. The exact math works out to 5.9 pulses per driveshaft revolution, which can be programmed for with the speed calibration tool in Tunercat or similar tools in LT1Edit.

SOLID LIFTER

no kidding

therckid

it was justa suggestion, gosh, the mor ehe argues the more he'll just take up space meaning the longer epope dont knwo whats wright. Its all in yuor best interest

SOLID LIFTER

Huh?

Z28ricer

iTrader: (2)

1. The autometer sender isnt even the same type of sender, its a 3 wire hall effect sender, good luck getting it to work directly with the LT1 pcm.

2. There would be no reprogramming for the pcm when using a T56 loaded one, he could simply sell the auto one and buy a manual one, or find someone looking to trade.

jfreeman74

I'm not about to buy another tranny. I have a brand new Pro-Built. I don't think I would want to trade that for any T56.

TexasLT1

Thank you! That is the answer I have been looking for. I was not aware that a Hall effect sender would not work. Now that I know that, I won't suggest using it anymore in the way that I was.





kidrcth, just stop, please I'm getting a headache.

TexasLT1

haha, don't worry, its not the transmission we're talking about selling/trading, its the PCM itself. Your trans will work fine.

jfreeman74

Oh, you had me worried that for a minute. I am beginning to think this swap is more trouble than it is worth. I found a 350 longblock for around $1300 that I may get. Take a look at my other post and tell me what you guys think.

TexasLT1

I don't know. With 72cc heads its going to have relatively low compression compared to the LT1, plus that cam isn't much of a performance piece. I guess it just depends on how much you could get a complete LT1 for and how much time you've got.

jfreeman74

It just seems like the 350 is going to a lot less time consuming. I could get them to put a bigger cam into the engine so I don't think that will be a real problem. I just starting to think that the LT1 is a bigger trouble than it is worth. I'm sure it would be a stronge engine but I don't know that the increases of the LT1 over the other 350 are worth the trouble and money.

pasky

Nobody needs a cheerleader.