another dilema...flywheel interchanges

[daveyboy]

seems that the previous owner of my 42 G506 installed at one time a 1938 block into my 1942 chevy truck, using the origianl trucks bellhousing! (I looked up the serial numbers, its a 1938 216 block)

Right now, my mechanic has just pulled the old (1938) engine getting ready to install the replacement (1958 block)

I bought a running 1958 block complete including starter.

his quick assement before going any further was that he noticed the mounting of the flywheels was different. (6 bolt vs 4 bolt) thats when he called me and stopped for the day.

(Bear with me.. I havent seen any of this yet. I am a distance from my mechanic, and am getting updates. I am only looking for answers so I can tell him how to proceeed with the minimal loss of down time. I didnt expect this sort of "hickup" in the project to happen)

his quick measurments says the flywheels diameters are the same for both (Around 14")

Anyway, the flywheel on the 38' block does NOT have the same mounting bolt pattern as the newer 58 block, so we need to use the flywheel from the 58, as it obviously came off of the engine.

problem is, the flywheel starter ring gear on the newer engine is a fine tooth. the old had a wide tooth.

MY question is simple:

Can I install this flywheel with fine teeth along with the matching fine tooth starter into the original trucks bellhousing, and the starter and ring gear will mesh properly?

Are the flywheel / crank centerline to starter drive pinion centerline the same distance in all applications from 38 onwards?

that is my question. Does anyone know this answer? Again, just trying to make life easier on my mechanic and give him some direction before he wastes more time.

My assumption is yes. However, I would like to know before I have him take even more time to install the flywheel and check the starter, etc. all time = money of course.

I quess I can scrounge around for a pre-54 flywheel with wide tooth pattern.
again. more down time though.

I have both starters in my hand here. Both starters apear that they would fit into the same bellhousing holes and mount up. so thats not an issue.

Now the clutch itself. I know the 58 had a 10" clutch. The original truck has a 10 3/4. According to my mechanic, the splines of each clutch disk are the same, so there should be no issues using either here

other than the reduced grabbing surface area of a smaller diameter clutch disk, I cant see a real probelm. I feel the 10" clutch setup should suffice for my needs.

what do you all think?

[dr deuce]

There are fine tooth ring gears (12v) and course tooth ring gears (6v). They interchange on the flywheels. A good machineshop chan change them. The smaller clutch should not be a problem

[daveyboy]

***UPDATE*** on the flywheel questions in case any of you have intentions in the future to install a later 235 in your truck.

the later flywheel with fine tooth ring gear as well as matching starter fit just fine into the chevy bellhousing. Starter engages and disengaes just fine.

I needed to use a smaeelr diameter clutch than the stock 10.75 diameter that was on the origianl flywheel.

the flywheel combo I used was for a chevy truck with a 10" diameter clutch. My guess is it will work out just fine.

All the clutch disks seem to have the same number of splines and same size diameter shaft, so all that was easily interchangable

The throw out bearing boith matched as weel.. So far, no issues here.

Thats my update.