T56 swap - answers to questions that arnt normally covered.

[Webmouth247]

ok i read through this thread and the other how to t56 thread and maybe i missed it but the answers im looking for seem to get loopped around. Lets start with this. My car is a 89iroc 5.7 tpi auto Q1. My speedo, is it worth getting the abbot box or better to get an autometer? and where do i get a abbot box at? does the autometer fit in my stock guage housing? and do i need a sgi-5? i dont care about cruise.... Q2. Do i need to change my ECM or get a chip? if so.. which? Just to verify.... which starter do i use??? I think i got everything else figured out i just dont quite get the wiring part yet but i guess that will come when i get started on the swap.

[thirdgenrs]

Originally Posted by Webmouth247

ok i read through this thread and the other how to t56 thread and maybe i missed it but the answers im looking for seem to get loopped around.
Lets start with this. My car is a 89iroc 5.7 tpi auto
Q1. My speedo, is it worth getting the abbot box or better to get an autometer? and where do i get a abbot box at?
does the autometer fit in my stock guage housing? and do i need a sgi-5? i dont care about cruise....
Q2. Do i need to change my ECM or get a chip? if so.. which?
Just to verify.... which starter do i use???
I think i got everything else figured out i just dont quite get the wiring part yet but i guess that will come when i get started on the swap.

LT1 Starter with a T56, I havent had a working speedo in 3 years. GPS FTW.

[TKOPerformance]

I've yet to read a post from anyone who uses an Abbot box. I looked at the option when I did my swap, and for $350 at the time it was not cost effective. I decided to run an Autometer speedo and a Dakota Digital SGI 5 instead. The SGI 5 sends a corrected VSS signal to my ECM and cruise module. Even with a mechanical speedo you still have a VSS in a 3rd gen if you have EFI.

The Autometer speedo does not fit in the stock cluster; you didn't really think it was going to be that easy did you? I built a new cluster to house mine and swapped all the gauages for Autometers at the same time.

Do you need to change the PROM? Maybe, maybe not. The car will run fine without a change, but you may get trans related SES codes. If you do a chip for a 5 speed car or a custom chip will solve the problem.

You don't need to use an LT1 starter, which tends to be expensive. You can use any small block starter for a 153 tooth flywheel. If the bolt holes are straght across it's for a 153 tooth flywheel. Stagged bolt holes are for a 168 tooth flywheel.

[Webmouth247]

Thanks TKO....
So what did your cluster run? Do you have pics of it in the car? I don't know if this is covered but what about switching to 91 speedo of cluster? Is that an option?

[TKOPerformance]

My new cluster cost about $500 by the time I was done. It is completely custom fabricated. PM me your email and I'll send you some pics. It looks awesome, but I am partial of course.

[tom86iroc]

i use the cable x box wasn't that hard of an install at all i just needed a cable made up with the right ends and length since i put it under my pass seat works perfectly no problems and its been in for like 5 years now and it's easy to configure and wire up

[(GYTR)-YAMI_SR]

where would you guys say would be the cheapest place to get the speedo conversion box? And i assume it will be easier with the motor out to to the master cylinder and pedals?

[TKOPerformance]

Not sure on the speedo box. The two places that offer them of which I'm aware are Abbot and JTR. Keep in mind that's dated information.

It makes no difference with the motor in or out doing the master and pedals. I didn't have mine out when I did my swap and it went smooth as could be. One thing I will advise is to pull the master cylinder bracket, associated hardware, and the pushrod mounting hardware from a T5 3rd gen in a wrecking yard. Using those parts it's an easy bolt in and it looks factory. The only thing you have to do then is cut the hole, and the firewall pad should be cut for it already. Use that as a template and cut from the inside. It's very straightforward.

[alloy]

JTR doesn't do the speedo mods anymore. Hasn't for a long time. I believe I'm the only one that does them now.

http://www.thirdgen.org/techboard/cl...xcellence.html (ALLOY = Excellence!)

[88 TA GTA]

Hi Everyone,

Belated Merry Christmas and Happy Holidays to everyone!

I wanted to say thank you to all that have helped here. Greatly appreciated.

I have a question about the bell housing cover or shield. No one has discussed this part. I bought a complete set from a 4th gen w/ pedals master/slave cylinder, bell housing, but it didn't come with a shield. I have read where some bought from Mcleod for 400 to 700 dollars. In other threads they mention NHRA rated scatter blanket/s. Is this part necessary for 320 to 350 HP?

Additional Pedal info: Mine didn't come with the wiring connectors, I pulled mine from a yard and even the front wheel drive sticks use the same wiring. Found mine in a 2000 Pontiac Sunbird GT I wasn't sure these would fit but they are identical.

Does anyone know what the pin switch (white) at the top of clutch pedal is for? (small two wire connector) It touches when the pedal is at rest (not pressed), I do not believe this needs to be connected to a 3rd gen, correct?

[Thirdgen89GTA]

Originally Posted by 88 TA GTA

Hi Everyone,

Belated Merry Christmas and Happy Holidays to everyone!

I wanted to say thank you to all that have helped here. Greatly appreciated.

I have a question about the bell housing cover or shield. No one has discussed this part. I bought a complete set from a 4th gen w/ pedals master/slave cylinder, bell housing, but it didn't come with a shield. I have read where some bought from Mcleod for 400 to 700 dollars. In other threads they mention NHRA rated scatter blanket/s. Is this part necessary for 320 to 350 HP?

Additional Pedal info: Mine didn't come with the wiring connectors, I pulled mine from a yard and even the front wheel drive sticks use the same wiring. Found mine in a 2000 Pontiac Sunbird GT I wasn't sure these would fit but they are identical.

Does anyone know what the pin switch (white) at the top of clutch pedal is for? (small two wire connector) It touches when the pedal is at rest (not pressed), I do not believe this needs to be connected to a 3rd gen, correct?

I know very few people who run a shield under 400rwhp. That is not to say that something catastrophic can't happen, but its an expense that usually doesn't get added till later. I'm not running one on my swap and its expected to go a little bit past 420whp(if I'm super lucky and hopeful)

[88 TA GTA]

Originally Posted by Thirdgen89GTA

I know very few people who run a shield under 400rwhp. That is not to say that something catastrophic can't happen, but its an expense that usually doesn't get added till later. I'm not running one on my swap and its expected to go a little bit past 420whp(if I'm super lucky and hopeful)

Thanks for such a quick response! Good luck on the 420WHP!

My 355 is mild, I was talking 350 HP at the flywheel not whp, so I'm sure I'm fine with a SPEC stage 1 and SC66S (for the 2 pc RMS) Would it offer any protection from the rear seal leaking ( I don't believe it would, but I have seen a few suggesting to replace the RMS w/install as it can damage clutch etc. if it starts to leak. My block was rebuilt very recently less than 5K miles so I was just curious.

Hey it took a couple hours to read through this thread so I made a short step by step version strictly from all that is listed here. I noticed the thread got chopped so I fixed that in the short version. Let me know if anyone wants it or where to post it.

Cheers and thanks again to everyone.

[88 TA GTA]

Hey Everyone I'm having a starter issue. I thought that with the 2 pc RMS block you could use the smaller gear after market racing starter?
My Spec flywheel was designed to be just as the original flywheel so shouldn't it bolt up and engage properly? It looks to be an inch out with the one set of holes and it touches it with the other.
Any assistance would be greatly appreciated.

[88 TA GTA]

Originally Posted by 88 TA GTA

Hey Everyone I'm having a starter issue. I thought that with the 2 pc RMS block you could use the smaller gear after market racing starter?
My Spec flywheel was designed to be just as the original flywheel so shouldn't it bolt up and engage properly? It looks to be an inch out with the one set of holes and it touches it with the other.
Any assistance would be greatly appreciated.

To answer the question above - yes it does bolt right up. Had to cut out a small corner on the starter block due to headers, but with that and adjusting rotation it works fine on the 153 tooth Spec SC 66S flywheel (custom for the 2 pc RMS), it was previously on the 168 tooth auto flywheel.

[TKOPerformance]

I am not familiar with every single combination over the course of the small block Chevy's production, but as a general rule there were two flywheel/flexplate sizes: 153 tooth and 168 tooth. Each uses its own starter. The starters have different bolt patterns, the 153 tooth version is straight, while the 168 tooth version is staggered. As far as bolting up to the block this isn't typically an issue because all but the very earliest engines are drilled and tapped for both starters because the factory didn't know which block was going in which car. Since the T56 setup uses a 153 tooth flywheel (a 168 won't fit inside the bellhousing; I tried one just to see) it needs the corresponding starter. I've heard of guys using the LT1 starter, but they are pricey, much like the aftermarket gear reduction units. I simply went to my local NAPA and bought a starter for a car my same year with a stick, which was less than $100 with a warranty. If it ever fails a replacement is cheap and available at a dozen stores. I had no header clearance issues either (Edelbrock T.E.S. headers). Long tubes are notorious for clearance issues though, so if you have them you may need to do some finagling.

As for the bellhousing vs. scattersheild debate I'd say leave it stock. Unless you are racing and it's required a scattersheild is really nothing but a waste of money and a P.I.T.A. The racing sanctioning bodies aren't taking any chances, and they don't require a scattersheild until you are running 11.99 or quicker, per NHRA. On a street car it's less of an issue, even with big power because the tires are the fuse. The tires will lose traction long before you shock load anything enough to cause a catastrophic failure like an exploding flywheel or clutch.

[88 TA GTA]

Thanks TKO

That's good to know, I am not so concerned about the scattersheild now.

I really wanted to use the mini starter because stock replacements would suffer from heat soak after a year, I replaced a few and each time it would be fine for a year and then after a 35 min drive, wouldn't start until she sat for at least an hour.I even tried a Ford solenoid on the fender which did help, but I installed it after last stock starter started giving up. This issue vanished w/ mini starter and it under $100 on ebay w/ 5 year warranty.

[TKOPerformance]

That's a good deal for a mini starter. When they first hit the market you were lucky to find one under $250. Chevy's with headers always have starter problems. The Ford solenoid helps, but doesn't eliminate the issue if the actual starter heat soaks. I have found over the years that reflective fiberglass backed blankets, aluminum heat shields, and ceramic coated headers all also solve the issue. 1 gauge battery cables and a big battery also help. I run an Optima in almost everything and they are usually 700-800 cca I believe. The only downside is the weight, but if placed in the well in the hatch area it can actually work for you to help with traction. That's where mine is. Then the big cable is even more necessary, because the length is much greater.

[88 TA GTA]

So its in, but believe one of the wires or maybe a fuse link?
My power mirrors, interior lights, headlights, parking lights, heater, (can't select anything - only fan comes on), radio, and digital odometer and Miles / KM selector doesn't work. The system check tells me that all is OK, the beeps and tells me trunk is open, a few seconds and then trunk open again.
I'm going to check fuse links first.....any ideas would be helpful, thanks in advance.

[88 TA GTA]

Haven't seem much talk about the t56 inspection cover. Is everyone running without it?
Can't seem to find this part anywhere