Gentlemen,

My baby has gotten to the point where it smokes blue so badly im embarrassed to have such a mint condition 85 305 HO L69 iroc with the 5 speed and have it smoking out a parking lot or a major intersection haha.
So I have been researching a lot and I am thinking of installing a 350 HO turn key crate. http://www.jegs.com/p/Chevrolet-Perf...37092/10002/-1 This one in particular.

However, I realize that these are configured and shipped with a flex plate and not a flywheel. Now I know some years had one piece and 2 piece rear seals, and weighted flex plates/flywheels etc. I want to know will my flywheel off my baby fit onto this crate without any vibration problems etc.
what is the flywheel on my car right now? weighted or not, size, tooth amount, etc I just want to make sure this swap goes flawless and this one part confuses me because I have read many answers on the internet and they were all different. I don't want to have my new engine shaking or the starter that comes with it not engage the old flywheel.

If its easier to just buy a new one would anyone know the P/N, size and tooth amount for this engine that will work?

Thanks a lot folks I am excited to breate some new life into her. (winter project)

1985 IrocZ 305 HO L69 5 speed manual
VIN#1G1FP87G0FL439612

 

Since I've done this very swap, I can give you part numbers later today when I return home.

JamesC

 

Actually I think you'll find what you need below on page 8:

http://www.chevroletperformance.com/...ine_Deluxe.pdf

JamesC

 

Kickass. That would greatly reduce confusion. Everything I've read online confuses me with this external/internal balance crap haha Thx a lot

 

Since we posted at nearly the same time, you may have missed my last post.

JamesC

 

Yeah I did haha. I see there are 3 manual trans flywheel options.
What flywheel did you use? I am oblivious to if mine is a 12 3/4 or a 14...
if it is a 12 3/4 the 14088646 option would probably be the best since it can accomadate different clutch sizes.

 

I used the 646 but the next clutch job I'm going to the 650.

JamesC

 

In addition to any of the ones posted above, any parts store can get you one if you ask for one for any model 86-92 5-speed V8 f-body.

 

Why not just change out your valve guide seals?

Not a lot of sense in buying a whole motor, when $25 of parts and an afternoon will fix it up like new.

This comes up ALL THE TIME. People always seem to WANT TO believe the worst possible, even when they have NO BASIS WHATSOEVER in an kind of FACT for doing so.

Here's a typical one from a coupla days ago, basically identical to yours almost word-for-word. https://www.thirdgen.org/forums/tech...ment-time.html

 

A smooth-running DD, sure, buy the parts. A lot more fun, and fun you won't regret, buy the motor and don't look back .

JamesC

 

85 has the flat tappet and 2 piece seals. Your flywheel will interchange.

 

Sometimes you just need an excuse to put in a ZZ4. Is that really so bad?

 

I live in northern Alberta, I have 6-7 months of winter to stare at my car sitting in the garage with a SLUG of a engine that leaks oil and blows blue smoke. I am a Cummins engine mechanic, building ISC, ISB, ISM, N14, and ISX engines for a living which some make 550+ HP. I don't want to work on this piece of gutless junk that can't make 200 on my days off. It dosent take me much convincing to say screw it and buy a crate engine. Plus, when the engine i'm planning to install blows up my T-5 trans ill have something else to do. But for now, winter project is the ZZ4. That along side my other hobby, all grain beer brewing.

I merely asked for some help since Diesel engines are my realm, not gas engines. Please don't try to make me change my mind lol

 

Also JamesC, checked out your site, I love your car, sort of reminds me of mine, in fact damn near identical, color and all(except under the hood haha). I attached a photo of mine. Keep her shiny and thanks to all for the help.

 

Very nice (and nearly a twin to mine).

JamesC

 

This from the manual:

Flywheel / Flexplate:
Like all small block V-8 engines produced since 1986, the 350HO Deluxe engine has a 3.00” diameter flywheel flange bolt pattern. Small block V-8 engines produced from 1958 through 1985 had a 3.58” diameter flywheel flange bolt pattern. This change in bolt circle diameter was made to accommodate a leak-resistant one-piece rear main seal.

JamesC

 

I am in the middle of doing a similar swap myself. Your flywheel off your '85 will not bolt onto the crate motor if it is a one piece rear main seal, exactly as the above JamesC post states. I have a flywheel here that will accommodate a one piece rear main seal and it has a casting number of 14088671. It will accept the smaller 3.00" crank flange bolt pattern,

 

Thank you very much for the imput I have ordered a flywheel and should be here soon as well as my engine. On a different note what are you using for a trans? Your stock t5 and driving sensibly or beefing it up? I'm planning to go JamesC's route and reuse the t5 and see how it goes. Anything you care to share ?

 

I was completely confused by the whole flywheel thing myself for a while: 153 tooth vs 168 (the 168 will not fit in the t5 bellhousing!) and then the different diameter crank flanges, balancing issues, etc.

I am also sticking with my stock t5 and not doing anything to it. However, I do have a later world class that I am using. There seems to be a lot of discussion on the t5s as well...

 

The following parts are ones that I used last time with the exception of the fly wheel (I'm going with the standard this time instead of the light weight):

Jegs part numbers

Centerforce II 183-CFT-360056
Centerforce I/II disc 183-384161
Throwout bearing 183-N1716
Roller Pilot bearing, which is recommended for this motor. 809-14061685
Flywheel 809-14088650. I noted that the Summit version is cheaper by $30 or $40, IIRC.

JamesC

 

eddietheripper

If your 85 has the original 2-pc 153 tooth flywheel, (PN 385678) Let me know if your interested in selling it. (My shipping ZIP is 02827) I've collected most of the T5 swap parts but both of the flywheels I've got right now are stock for 86+ cars and I still need a 2-pc RMS #385678 Flywheel.