Jupiter

iTrader: (1)

I am looking for a list of flywheel choices for my lt1 T56 swap onto a pre 86 sbc with 2 piece rms. I know the Centerforce 700107 but surely there are others?

P.S. will my 3rd gen torque arm fit with the T56 or do i need a 4th gen torque arm?
Answer is = YES a 3rd or 4th gen will fit. there are two diff types of mounts though!

Flywheel's with neutral balance for 2 piece rms pre-86 sbc + lt1 T56... 'that i have found so far'
Fidanza - 198661 13.5 lbs.
Ram Clutches - 2555 18 lbs.
Spec Clutches - SC66A 13.2 lbs.
Spec Clutches - SC66S 25.9 lbs. steel
Centerforce - 700107 35.5 lbs. steel
McLeod - 460370 25 lbs. steel
American PowerTrain - FWCV-11006 32 lbs. steel

I am expanding this post because i am finding other parts that need to be found and documented. I already have a Ram adjustable master cylinder installed with a slave bearing so i will need to get a slave cylinder to attach to it and get rid of the slave bearing. I notice there is no bleeder option on the factory replacement slave so how does this get bled? Am thinking it may be best to get a after market slave with a bleeder option. I'll look for which ones fit and list them here. If anyone has any part#'s for aftermarket slave cylinder with bleeder provision, please let me know.


What about driveshaft? Which driveshaft is needed for this conversion? I have an aluminum 1LE 3rd gen shaft and a custom 3" aluminum for my T10 which i know is to long. Will my 1LE shaft fit or will i have to cut my 3" down and to what length?

P.S. by the way guys i will probably want to sell the T10, shifter and, driveshaft once i am done with this conversion. The tranny is an upgraded BW 'Super' T10, Hurst Super Competition shifter and custom Coleman 3" aluminum driveshaft. I also still have all the mechanical linkage, pedals, bellhousing, universal electric/mechanical VSS and, Ram hydraulic slave bearing.

jmd

iTrader: (4)

Off the top of my head,

Spec has one listed on their site. It's an S66something PN. It has threaded holes to bolt a weight onto it for a 400 balance type 383 or 400. This one does not work with the cheap aftermarket weight plate that bolts between the flywheel and crank because the clutch fork range of motion doesn't release the clutch.

The Centerforce for 400 SBC / LT1 T56 works great. And don't count Centerforce out just because you don't see a part listing for them. They make the 700107 and the 400 one but it's not really listed anywhere. But on Summit and everywhere else, the neutral balance 350 one is listed.

3genpio

iTrader: (6)

I have alu fidanza FW with steel friction disc, they have opne model for LT1 t56 bolted to 2 piece rms.
Tork arm from 3 or 4 gen doesn;t matter only problem you can have is tork arm mount as there was 2 model of it, with torq arm lips facing the inside of the car or outside the car, but prothane and ES make both kind of them just need to know wich one you have.

jbradhill

Does anyone know if this is a compatable flywheel for the 2pc rear seal to LT1 T56 swap?
Zoom flywheel Part No. 60-3209
Thanks, Brad

jmd

iTrader: (4)

With a Ram concentric hydraulic throwout bearing and third gen clutch, yes.

With a 93-97 external slave and Valeo pull clutch, no.

jbradhill

So I think the answer is no since I bought a 97 LT1 T56 to replace the 700R4.
I am trying to find a lightweight flywheel that isn't costing a fortune.
I tried twice to order the Fidanza listed above and they weren't in stock

DanZ51

Keep this post alive. I'm trying to find an "affordable" flywheel. These conversion flywheels have gone from expensive to stupid ($600 WTF). The American Powertrain is top of my list at "only" $350

DanZ51

JMD How did you come up with that? I've searched both the Ram and the Zoom flywheel and haven't found anything about needing a hydraulic T/O bearing to function. Not saying your wrong, but where is the info

Jupiter

iTrader: (1)

Yea that would work with an LSx T56 + other parts. The LSx T56 uses a concentric bearing as the slave. I personally would have preffered that type of system but alas i got what i could afford, an LT1 T56... lol
By the way i'm currently using a Ram concentric TOB with my BW T10. BEST clutch pedal i have ever had with an old school 4 speed. The clutch pedal feels EXACTLY the same every time i press it. Unliker the old mechanical clutch which felt different every single time i would press it. And of course there is the 'health benefits', it is much easier on the knee in traffic.

jmd

iTrader: (4)

The one he posted is a "regular depth" flywheel, not a deeper LT1 T56 style flywheel.
Because of that, a concentric hyd. throwout bearing is just another way to do it.
McLeod's first design was too tall in depth measurement (refer to their "A" measurement on their diagram) but it's been a decade since I had that one.
I can't find Ram's right now but it's also been years since I researched this stuff.

Jupiter could potentially sleeve his LT1 T56 TOB sleeve and re-use the parts he has. The only two concerns there are what design is used to retain it from rotating and the T10/T5 TOB sleeve bevels down at it's base vs. the flat surface at the base of the LT1 T56. My T56 is sleeved for a larger o.d. but I went mechanical linkage so I could use 82-83 f-body fork & TOB.

Jupiter

iTrader: (1)

Ah yes i remember now. I ran into this when doing my T56 research. It came out as a more expensive solution so i discounted it for my poor ****. BUT if i could afford it i would for sure go this route. Using a Tranny spacer and a Ram 78160 concentric bearing you can attach a LT1 T56 to a pre 86 sbc. I have found the spacers for about $225 and the bearing for $350. So although this is the more elegant solution in my personal opinion, it is also more expensive.

jmd

iTrader: (4)

How much spacer is Ram telling you the 78160 requires?

There are just so many ways of doing it.

Jupiter

iTrader: (1)

I don't remember!

Jupiter

iTrader: (1)

I have updated the flywheel list with weight info.

I think the Ram aluminum flywheel should work fine for me. My existing flywheel is a steel GM Performance part that weighs 25 lbs. so the Ram is not much less at 18 lbs.. If anyone has some good input as to why i should chose another please let me know. I'm gonna think this over for the next couple of days before i order. I kinda feel i have plenty of lower end torque to make up for the momentum loss from a liter flywheel. I've never launched with an aluminum flywheel so i don't know what it feels like BUT when i got my car it had the oem 35 lbs. flywheel and i really don't remember feeling it much different then the gm performance part. But then again i didn't have as much power when i did that change... lol

online170

Wow, when I did my swap in 2008, I must have searched for a week, and there was only the Centerforce and Fidanza ones available for the 2pc RMS.

jbradhill

I bought the RAM #798-2555 AL flywheel $$420and have it installed w/Tranny. Still have to do the finishing touches (reverse light, torque arm and drive shaft). I'll let you know how this ends up.

Jupiter

iTrader: (1)

I'm leaning towards the Ram as well. I think it provides a good balance, not to heavy or to lite. My next thing to figure out is the driveshaft. I need to find out the proper length. I have an aluminum 1LE driveshaft and am wondering if it will be the right length. If not it is for sale... lol I will then have my Coleman aluminum shaft cut down to size. If someone knows the proper length i need please let me know.

Jupiter

iTrader: (1)

Ok so after lot's of hemming and hawing i decided on a middle ground. After speaking with Ram and Spec tech support and several friends invloved in racing i decided to order the Spec steel flywheel. They i guess understood i wanted something lighter in steel so they made it 22 lbs..

jmd

iTrader: (4)

That's a pretty choice weight and my experience with the Spec piece is good.

DanZ51

Nice. So they lightened it for you? If you don't mind me asking, how much?

Jupiter

iTrader: (1)

Yes it appears so because they told me their standard weight for steel flywheel is 25.9 lbs.. What i recieved is 22 lbs. Keep in mind that American Powertrain also offered to lighten one up for me for some more duckies. GM Performance part flywheel i was using is like 25 lbs.. The oem part was like 36 lbs.

heh, if you mean price, it was $359+shipping

383tpimachine

http://www.summitracing.com/parts/ctf-700173

BAM this is the fly for a 383/400 2pc rms with a t56 and the one I will be running behind my 400 in my vette. LET er eat

Jupiter

iTrader: (1)

Well i took her out for a ride yesterday and all i can say is WOW

I swear this transmission was designed for my setup. The flywheel is amazing. I have no problem with 'stalling' because it's only 22 lbs., but yet i do feel it revs slightly quicker. The clutch disc is organic/organic and very forgiving of course. For the price and quality 'so far', i would recommend this flywheel.

jersyboyy

iTrader: (8)

you got a part number or did you just call them??

383tpimachine

called then verified with an email to them and an email to summit. All stated that was the correct fly

Jupiter

iTrader: (1)

If your reffering to me. I emailed Spec then called. For the steel part# SC66S the price of '$359' i think is the best choice. It came with the external balance weight screwed on, all i had to do was remove it for my internally balanced engine. If you look at the first post, i have already listed all the part #'s.

Pecoz96

Will that wheel work on396 bbc? That swap is what im in the misJt of doin thanks

jmd

iTrader: (4)

Yes. A 396 or 427 accepts the same flywheels as any 85-down 2pc rear main seal 350 SBC. Same crank bolt pattern and balance. But, you'll want to make sure the block is correctly drilled & tapped for the 153 tooth flywheel compatible starter bolts.

Sojer

So a basic 500hp 383 85 block which is the cheapest flywheel? Any lt1 clutch will work. With about 1400 for a built 700 and converter the swap should be around the same price

jbradhill

I made one major mistake in my purchase of the Al flywheel. I forgot that my 383 had a 400 crank "externally balanced" and the flywheel was neutral balance. I didn't realize this until I fired up the motor w/o tranny and felt the out-of-balance condition. I ended up paying another $200 to have a machine shop drill&tap to get the correct counter-balance to match the initial setup.

... just a reminder since it is not the same as the normal 350 SBC crank.

jmd

iTrader: (4)

That's why the OP started the thread. So you could make use of the internet to which you're connected and your heart out to find the best deal.

Sojer

The have different snout sizes and other difference. As u see this post is old so that means I was looking. I don't know about transmission

Casey Meyers

iTrader: (2)

I'm running a 87 up block, 383. Uses a neutral balance flexplate and swapping to a T56. Confirmed with the engine builder, they said I can use the LT1 flywheel. I'm mostly concerned about clutch and flywheel hardware and flywheel weight. I see weights from 9 pounds to 36 pounds. I don't daily drive my car. Duration of the cam gives it a lopey idle, will be idling around 900 rpm. Mainly back road sprints, would like to get into road course racing, and I do drag race on occasion, mostly just street pulls. any recommended weight?

jmd

iTrader: (4)

These two things contradict each other. I went back and read your last thread too.
If it's got a weight, it may be balanced the same as all 86-up 305 and 350 variants and work with the LT1 flywheel. If it has no weight, then it is neutral balance and you'd have to have an LT1 flywheel neutral balanced every time you replaced it.

I had the 16lb third gen flywheel and a healthy cam in a 305; didn't bother me a bit. A heavier one is going to make it just a bit easier to drive; not slow you down. Aim for 15 to 25 IMHO.

jmd

iTrader: (4)

All the ones listed by the OP work with the pull clutch 93-97 F T56 on a pre-86 chevy. If you have a question, post more detail.

Casey Meyers

iTrader: (2)

Alright, thanks. I can't remember which is which, the 86 305 uses a different flexplate than what the 383 needed, and its the same flexplate as a 90 4.3 and a 98 350

Sojer

400ci sbc crank and 454 crank stock are externally balanced so the used different flex plate or flywheel

jdpolzin

Any of you guys have an externally balanced 383 or 400? I bought the SPEC SC66S-400 conversion flywheel which comes with a spacer plate that goes between the crank and the flywheel. I'm having issues with the clutch fork hitting the pressure plate. I cant even engage the clutch before it hits. Now I've talked with "Jeremy" from SPEC, not a real easy guy to deal with. He says the spacer plate is the only way they have to counterbalance the wheel. I would have thought a bolt in style would be better so your not spacing the flywheel out any towards the trans. I'm wondering if any of you guys with 383's are using this spacer plate?

online170

I have no experience with it, but that sounds wierd. I didnt know such a creature existed.

In auto trans applications, whenever you spacer the flexplate or torque converter out, you have to spacer the trans out by the same amount to avoid issues that you're facing.

I'd be interested to learn about this. I couldnt find any images of the spacer you are referring to, and cant really picture how it goes.

DanZ51

A little info:

http://static.speedwaymotors.com/pdf/916-15375.pdf

jdpolzin

OK, well I was able to talk with another tech guy at SPEC that was much more helpful than the previous guy. I was also able to actually get some simple answers that I couldn't get out of the previous guy. When I ordered my flywheel, I told them I had a 383 so they sent me a flywheel for a 400 motor. Well, like we have posted, the actual 400 chevy motor uses the spacer counterbalancer. My motor only needs to have a flywheel that is simply externally balanced so I should have received the same flywheel that you guys did.

One of my questions was "is the distance between the crank and the flywheel surface the same between the standard sc66 and the sc66-400?" The previous guy wouldn't answer that question. This guy did, and yes the actual flywheel is the same one, just that the -400 is sent with the spacer. So....that's why my flywheel sits so far towards the darn trans and doesn't work! The spacer is roughly 3/16" thick.

I went ahead and paid for the external weight so they are shipping that to me now. Hopefully this time around is better than the last! Now I just need to go out and remove the exhaust, trans, center counsel, shifter, crossmember, clutch and flywheel again! FUN!!

jdpolzin

Man, I shouldn't have went with SPEC. Just so future people researching this can have my opinion, I'm posting my experienes. Go with someone else besides SPEC. Customer service is horrible, if you end up talking with a guy named Jeremy at SPEC, you'd be better off just beating your head on the wall because the guy is a complete jerk and very unhelpful. After all of this, I need to pull my exhaust, center counsel, shifter, driveshaft, clutch and flywheel because they sent the wrong part. I even called them before I installed it to tell them I didn't think it was going to work. This Jeremy guy said "there is no bolt in weight" even though he knew exactly what I was doing. He simply wanted to be a jack ***. Now, I went ahead and ordered the weight, which has a shipping weight total of 1lb. They tell me $10 but when I get my invoice, they charged me $26 shipping!!!!!!!!!!!!!!!! WTF!!!! I guess they aren't looking for return business. Hopefully when I get everything apart and re-installed, it works without more hassles.


In smmmary, if your doing the SBC to T56 conversion flywheel. Buy from Centerforce or one of the other companies. SPEC isn't worth the savings in cost.

nosajwols

iTrader: (1)

Good to know, I was just about to pull the trigger on one.

jdpolzin

Go elsewhere. I talked with Centerforce about this issue and they mentioned they have had quite a few calls from people who have purchased these from SPEC. Seems I'm not the only one. Of course when you talk with SPEC, "I've sold thousands and thousands and your the only one I've ever heard that had a problem." I quick google search ended that statement.

jdpolzin

And for more future reference, here's a link from this site with another SPEC conversion flywheel that was too thick to allow the clutch fork disengage even without using a spacer. I'll keep you guys posted on how mine ends up once I tear it all back apart again.

https://www.thirdgen.org/forums/tran...utch-fork.html

jmd

iTrader: (4)

It's good you're persevering. When I troubleshot one, the weight was 0.100" thick and had worked fine with the T5 and thirdgen flywheell on a 400. It just ended up being an easier transaction to buy the right Centerforce and sell the SPEC. At the time, no one listed the Centerforce so I had to call them.

jersyboyy

iTrader: (8)

in case anyone is still looking for one, i blew up my 383. I have a externally balanced 383 2 pc rms centerforce flywheel im currently selling. been resurfaced 200 miles ago.
and a bunch of other parts from the t56 swap

WG383

Hey, Newbe here...
i would be interested in these swap parts for a old school 383

reading this about T56 flywheels i was lucky enough to come across a Wier kit and flywheel was easy just used an old school 11 inch setup and the kit came with hyd throw out bearing.
my thought is why cant you just use the LT1 bell and an old 2 piece main seal flywheel and a hyd throw out bearing? i am getting ready to do a second converson that is how i came across this tread.

please bear with me as i learn the ropes this is the first message board i have ever joined.
but lots of good info and ideas.

so what swap parts do you have, this is on an old 2 piece main external balance motor as well.

i hope i did this correctly....
if not please correct me.
thanks