Where do I go to determine which parts I need to install an M20 on my L98 383, in my 69 vert? For example, I know I need a pilot bearing but there are a huge number of options; which one? Same with flywheel, clutch, and shifter... I don't even know if I'm missing anything.

 

I’m sure there are way more experienced people here but I need to consider the follow
bellhousing type
Clutch linkage/fork or hydraulic throw out bearing
flywheel
clutch kit
pilot bearing
shifter type
im sure im missing something. Lots of threads here and I spent hours researching, good luck.

 

Everything I read says when you buy a pilot bushing.....make sure it is oilite bronze.......and non-magnetic. Many sold today have some level of steel in them,....which will wear the shaft.

If your frame was built for an automatic, you will need to buy and weld on the bracket on the upper left frame where the cross-shaft bar mounts.....with the other end mounting on a ball that screws into side of engine. There should be a threaded hole there on the engine for this already if its a Gen 1 SBC..

Glassgoat meantioned hydraulic throwout bearing........which may be an option, I don't know....but Chevy used a mechanical setup, which includes that cross shaft mechanism, pushrods, springs, etc.

Then there is all the pedal mechanism that has to be converted to add the third pedal. As you mentioned, the entire shifter setup needs to change.

Its all possible, and best way to do it is just use the AIM, obtain all the parts Chevy used on manual transmissions. Its all available from Zip Corvette or other vendors....look at their catalogs, the parts diagrams witll show you what you need. I think its worth it... manual transmission is what makes a Corvette a sports car...

 

@CorvettePassion Thanks... I realize I forgot to mention that the car had a manual transmission, so it already has the pedals setup and I believe the mounts are going to work. When I bought it (bought from Steve at SoCalVettes), Steve recommended the Muncie wideband and said that that will work with the L98 block. When I get home later today I'll crawl underneath and take some pics to post to this thread.

I'm missing something key here (this falls within the "no such thing as a dumb question" box)... What's "the AIM"
What prompted the post was that I went to Summit, searched for a pilot bearing and filtered by the SBC 350, got back over 30 entirely different choices with options such as the metal type, style, measurements... all of them different. I'm thinking "I'm clearly missing some key to making this choice." And that's the thing: do I go to a manual for a '69? The vette was originally a coupe, torn down to frame and built as a convertible, very custom. But I suspect that there can't be that many options if he was using a 427, right? So I guess the question comes down to "where do I get the details to make these choices?" or maybe "Does anyone have a recipe?"

 

The AIM is the factory Assembly Instruction Manual, available through various vendors:
https://www.corvettecentral.com/c3-6...nual%2f1969%2f

I seem to recall you're using an aftermarket stroker crank, you could contact the manufacturer and ask about a pilot bearing recommendation.
Or measure your crank and tranny snout to see what will fit.

 

As you are putting in a Muncie, this may not be required but it is recommended - you should measure the concentricity of the bell housing relative to the crankshaft centerline. Offset adjustable dowel pins are available to “dial-in” the location of the bell housing. This is needed if you were to install a Tremec as that transmission is unforgiving of ill-aligned bellhousings. The Muncie is forgiving, up to a point. Having spot-on concentricity will make all components, including the throw out bearing, play happy together.

 

huh, that didn’t occur to me. I haven’t gotten my hand on a bell housing yet; there’sa choice?

 

Found a pdf online…
69 AIM pdf

 

The 3899621 housing is the most common, having application in most of Chevrolets GM built back in the day, including the Corvette. It is cast aluminum so if a flywheel or pressure plate or clutch disk were ever to let go, you’ve have the potential for injuring your lower legs. There are several aftermarket companies that sell steel units that will protect you. McLeod, Lakewood and QuickTime are good choices.

 

I recently purchased the Silversport 621 reproduction bellhousing for my 408 sbc and will be buying another for my 69 big block. They are top quality, very nicely machined and thicker and heavier than stock. And cast and machined in USA. I highly recommend it.

if you want something less expensive, I,ll sell you my original off my 77 for $100 plus shipping. It’s in perfect condition. PM me if interested.

if you really want overkill strength with SFI ratings see my ad on parts for sale for QuickTime steel.

 

You need the National pt# PB-656-HD pilot bushing. This is the correct "oilite" bushing that most like to use and is a proven part.
Flywheel size is determined to whether or not you are using an 11" or 10.5" clutch......the flywheel sizes are 168 tooth for 11" and 153 for tooth for 10.5".......the 153 is smaller and lighter if you are buying a new clutch but most use the 11" for strength....but a quality 10.5" clutch will work fine. But I would just get an 11" 168 flywheel and corresponding clutch....
Most of us here recommend McCleod for a clutch and I am one of them......the Super Street Pro McCleod is the best street clutch on the market IMHO......and the pedal effort and engagement is perfect.
You will need the short Timkein pt# 614018 Throwout bearing.....
You will need the correct clutch fork.....get one from a Vette vendor......
I run a Hurst shifter....and I love it.......some like the Long better but they are pricey......
I just installed a M20, Hurst, Pilot bushing, 10.5" McCleod clutch, New fork, fork pivot, and Throwout on a 350 I just built going into a 56' Chevorlet, just last night.....this is why this is so fresh in my mind....LOL.
BTW, Stick the pilot bushing in the freezer and use the back side of the right size inpack socket to drive it in....thereis a lip on the crank flang that the socket can go into to help guide the bushing in straight.......
Try to find a cutoff piece of input shaft to use as a clutch tool......the plastic jobby in the clutch box will get you close but not spot on if you don't know what you are doing.......if using the plastic tool......if the trans does not just slide in, have a buddy actuate the clutch fork a tad to loosen up the disc and the trans will slip rich in.......

Good Luck,
Jebby

 

I just put a McLeod Super Street Pro (#75221) clutch in my '80 and what @Jebbysan said is correct. It has a nice, smooth, engagement and the pedal effort is very nice. It is way lighter than the cheap "perfection clutch"-brand unit that came out of my car. The Super Street Pro should also be more than strong enough for your 383 L98. The clutch comes with a pilot bushing, but you should throw that one in the trash as soon as you open the box. Its magnetic. The National PB-656-HD is what you want and can be had at nearly any O'Reilly auto parts, Summit Racing, or RockAuto. Freeze it overnight before the install and it will tap right in.