Transmissions and DrivetrainNeed help with your trans? Problems with your axle?
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They put an NVG 3550 in there with the same 1" 14 spline input shaft. I almost bought one back in Indiana but I let it go. It's pretty scary to drive!!
They put an NVG 3550 in there with the same 1" 14 spline input shaft. I almost bought one back in Indiana but I let it go. It's pretty scary to drive!!
That one in the Summit link that Z28 posted is the one I'd use. I sure as hell wouldn't want to use a puny 9-1/4" disc behind a V8. The Summit one is the right diameter for the V8 pressure plate, and it has the correct 14 spline hub for the V6 T5. Should be a perfect fit.
__________________ 89RS w/350 TPI; 69RS/SS w/450 HP 350/Muncie 4-Speed "Too weird to live, too rare to die."
Dont know if you can fit an 11" disc, plate, flywheel into a T5 bellhousing, but heres the disc to use if you are using an F body 10.4/5" setup.
The Fbody flywheel actually takes an 11" clutch disc. I'm not sure why they opted to use the 10.5" on the fbody, but the flywheel is the same part # as the Corvette, which is 11". Probably because the fbody only got the 305, and
not the "ultra oh so fast L98". heh.
The difference is the pressure plate and disc. The corvette pressure plate is designed a little different around the bolt holes to hold the clutch. The bolt pattern is the same 11.5" as the fbody.
So if you want to use a 11" disc, then order a pressure plate for an '87 Corvette.
Joe, you may know more than I on this one, but everything I have ever read about someone trying to use a true 11" clutch with the stock f-body T5 bell housing didn't work out. A full 11" clutch requires the 168 tooth flywheel, which deffinitely won't fit. - You sure it's not a 10.75 or metric equavalent that's maybe slightly under a full 11"? - Yes, the factory f-body flywheel is a funky bastard that's been fly-cut to no end.
Joe, you may know more than I on this one, but everything I have ever read about someone trying to use a true 11" clutch with the stock f-body T5 bell housing didn't work out. A full 11" clutch requires the 168 tooth flywheel, which deffinitely won't fit. - You sure it's not a 10.75 or metric equavalent that's maybe slightly under a full 11"? - Yes, the factory f-body flywheel is a funky bastard that's been fly-cut to no end.
Well, I used to think the same thing. The best thing I can offer is to measure my clutch disc, and post a picture.
Do you consider the T56 clutch 11"? because its the same thing I'm using on my ZF6, with a T5 flywheel.
Hey Joe. I guess you decided to ditch the idea of a T5 in the Vette and went with the ZF6 instead? What you said about the 11" clutch got me curious so I went out in the garage and looked. With the 10.4" disc on the lightweight flywheel, it looks like there might be another 1/2" between the bolt holes, but the actual contact surface only goes maybe another 1/4" past the edge of the 10.4" disc, due to all the extra metal they remove on the lightweight flywheel. I also tried it on the heavier TBI flywheel, and it looks like that'd be more feasible since the contact surface goes all the way to the bolt holes. Either way, I don't think I'd go too far outta my way to use an 11" clutch anyways. From what a lot of clutch companies say, the 10.5" clutch is more than adequate behind just about any SBC. Now a BBC on the other hand, I'd probably feel better running the 11". I upgraded to the 11" in my 69 Camaro, but the 10.5" that was in there before seemed to work just as well. When I did change it to the 11", I did use the 168 tooth flywheel with the dual bolt pattern, and I also had to use the BBC style starter with the staggered bolt pattern and the smaller nosecone. Luckily a buddy of mine sold me one of the highly sought after "621" casting bellhousings that go for $200 on ebay for a paltry $20.
__________________ 89RS w/350 TPI; 69RS/SS w/450 HP 350/Muncie 4-Speed "Too weird to live, too rare to die."
Hey Joe. I guess you decided to ditch the idea of a T5 in the Vette and went with the ZF6 instead?
Not exactly. I DID the T5 swap in the vette, to prove it can be done. I've got a company now making T5 adapter brackets for vette folks. I've got about 5 guys on the corvette sites who are doing the swap now. For a stock vette, especially a guy with an auto (2.59:1 rear) it's a great economical way of getting a manual trans.
But I just did it to prove it can be done. Once I was done and tested it out, I pulled everything apart and started putting the ZF6 project together.
Quote:
Originally Posted by Pat Hall
What you said about the 11" clutch got me curious so I went out in the garage and looked. With the 10.4" disc on the lightweight flywheel, it looks like there might be another 1/2" between the bolt holes, but the actual contact surface only goes maybe another 1/4" past the edge of the 10.4" disc, due to all the extra metal they remove on the lightweight flywheel. I also tried it on the heavier TBI flywheel, and it looks like that'd be more feasible since the contact surface goes all the way to the bolt holes. Either way, I don't think I'd go too far outta my way to use an 11" clutch anyways. From what a lot of clutch companies say, the 10.5" clutch is more than adequate behind just about any SBC.
Which to the best of my knowledge is the "lightweight" flywheel used on
the HO 5.0 fbody, and the corvettes. Is this the same as the one you measured?
Quote:
Originally Posted by Pat Hall
Now a BBC on the other hand, I'd probably feel better running the 11". I upgraded to the 11" in my 69 Camaro, but the 10.5" that was in there before seemed to work just as well. When I did change it to the 11", I did use the 168 tooth flywheel with the dual bolt pattern, and I also had to use the BBC style starter with the staggered bolt pattern and the smaller nosecone. Luckily a buddy of mine sold me one of the highly sought after "621" casting bellhousings that go for $200 on ebay for a paltry $20.
Heh. Keisler sells those "621" knockoffs for $200 now as well. Saw an ad for
C4 owners. I sold one last summer for $25 before I realized how much people want them. dumbass!
Anyhow. There is still a good possibility the T56 + Corvette use a "metric 11" or "10.75 sold as 11". This probably needs a bit more investigation, but I'm going on what I've been subject to lately. I spoke with the guys at Fort wayne about it, and they said the difference was the pressure plate is machine different. On the Fbody pressure plate, the bolt holes are like 1/4" away so the hex head would hit the disc, where the Vette plate uses a longer bolt and the head is farther away allowing more clearance for the disc.
When I switched to the vette PP I think I had to go from a 3/4" bolt to a 1 5/8" bolt FYI.
Hey Joe, yeah that flywheel in the pic looks pretty much identical to the one I've got. The only reason I got my "621" housing so cheap was I bought it probably about 12 years ago before the insanity of ebay auctions really came about, and also the fact that the guy I bought it from had a pretty steady drug habit to support. Lol. Keisler is probably one of the most overpriced trans places I've yet to see. The prices for their "perfect fit" TKO trannys are nuts! That ebay seller "KajunJon" has the repro 621's for about $160, which is the cheapest price I've seen for one. They really do look like a nice, quality made piece (T6 aluminum, CNC machined, etc.). Luckily my original one is still in perfect shape. I've seen tons of cracked and broken ones at swap meets. Some joker at a swap meet last summer was asking $100 for one that was missing a big chunk where the starter nose goes, and also had a crack that ran almost all the way to the trans mount area. He said it'd be fairly easy to fix. He also had a Muncie with a couple of broken ears, stripped bolt holes, and needed a total rebuild, for the low bargain price of $600.
__________________ 89RS w/350 TPI; 69RS/SS w/450 HP 350/Muncie 4-Speed "Too weird to live, too rare to die."
Hey Joe, yeah that flywheel in the pic looks pretty much identical to the one I've got. The only reason I got my "621" housing so cheap was I bought it probably about 12 years ago before the insanity of ebay auctions really came about, and also the fact that the guy I bought it from had a pretty steady drug habit to support. Lol. Keisler is probably one of the most overpriced trans places I've yet to see. The prices for their "perfect fit" TKO trannys are nuts! That ebay seller "KajunJon" has the repro 621's for about $160, which is the cheapest price I've seen for one. They really do look like a nice, quality made piece (T6 aluminum, CNC machined, etc.). Luckily my original one is still in perfect shape. I've seen tons of cracked and broken ones at swap meets. Some joker at a swap meet last summer was asking $100 for one that was missing a big chunk where the starter nose goes, and also had a crack that ran almost all the way to the trans mount area. He said it'd be fairly easy to fix. He also had a Muncie with a couple of broken ears, stripped bolt holes, and needed a total rebuild, for the low bargain price of $600.
Ok. Last night I measured the clutch disc. EXACTLY 11" diameter. The disc fits on the flywheel with a hair to spare before contacting the bolt holes. So we know a 11" clutch disc works fine with the 153 tooth flywheel.
The issue is the pressure plate. It seems that a lot of "old school" OEM pressure plates for 11" discs use the larger bolt pattern found on the 168 tooth flywheels. However, the corvettes + LT1 Fbody use the 11" disc with a 153 tooth flywheel. Basicly, on the T56/ZF6 pressure plate the bolt hole bosses are raise 1" so the hex head doesn't crash into the disc.
If you order a pressure plate for a 1987 Corvette it will work with a 10.75" disc.
So the question is, who makes a push-type pressure plate with the raised mounting bosses to run a sprung 11" disc on the 153 tooth flywheel? I'm sure lots of people do.
What about a LS1 T56 clutch? It should be push style, on a 153 tooth flywheel..
He said it'd be fairly easy to fix. 
He also had a Muncie with a couple of broken ears, stripped bolt holes, and needed a total rebuild, for the low bargain price of $600. 
