My question is, which flywheel did they use in my stock 73 with manual trans.  

 Look at your starter mounting bolts. If they are straight across from each other, the car has a 12 3/4" 153 tooth flywheel.

If the bolts are staggered, then the car has a 14" 168 tooth flywheel.

I believe that your '73 had a 14" FW. I could be mistaken though. What are you going to do the car regarding the FW? Just curious.

 Thanks for the reply! I knew somebody knows something about it. Well, what I am doing is building a new motor for the car. A 383. I have been buying motors parts for the last 6 or 8 months. It is an internally balanced motor. I was thinking about using a new flywheel but everyone tells me to just use the one I have. Not sure, but I may do this. I do have a new Center Force Clutch, part no. DF148552, 11inch dia., 1 1/8" x 26 Spline. I was wondering what starter to use. I saw a brand new one on E bay yesterday that is a Mini 2 h.p. good for about 450 h. p. and 11 to 1 compression ratio on the motor. I ended up with it for about 85 bucks. My comp. should only be about 9.5 to 1 and around 400 h.p. Any way it is good for 153 or 168 tooth. I tried to feel the bolt pattern on my starter and it felt like the bolts were offset. What are your thoughts about using the old fly wheel. This is the first motor I have built so I am kind of learning along the way. Lot of fun and MONEY of course. Thanks Again!!

[QUOTE=Silver73] Thanks for the reply! I knew somebody knows something about it. Well, what I am doing is building a new motor for the car. A 383. I have been buying motors parts for the last 6 or 8 months. It is an internally balanced motor. I was thinking about using a new flywheel but everyone tells me to just use the one I have. Not sure, but I may do this. I do have a new Center Force Clutch, part no. DF148552, 11inch dia., 1 1/8" x 26 Spline. I was wondering what starter to use. I saw a brand new one on E bay yesterday that is a Mini 2 h.p. good for about 450 h. p. and 11 to 1 compression ratio on the motor. I ended up with it for about 85 bucks. My comp. should only be about 9.5 to 1 and around 400 h.p. Any way it is good for 153 or 168 tooth. I tried to feel the bolt pattern on my starter and it felt like the bolts were offset. What are your thoughts about using the old fly wheel. This is the first motor I have built so I am kind of learning along the way. Lot of fun and MONEY of course. Thanks Again!![/QUOTE]

if you use the old one.. have it turned..

 

The larger flywheel will cause the engine to turn more slowly, all things being equal.  But it will produce more torque to the crank if the engine is hard to turn.

The smaller flywheel will spin the crank faster, but produce less torque.

Depends on what you want to do.  You can get a high torque starter that will help either way.  If the engine will be hard to turn, you will need the torque.  If not, the extra speed is nice to help start easier.

FYI: If your using a '86- up block w/ a one piece crank seal you cannot use your existing flywheel. Bolt pattern is different. 3.00."

If you are using your original engine and flywheel for the 383 build up. Have that flywheel checked out for fatigue/heat cracks first. It may be ok to have turned, but I'd rather see you be safe than sorry. It's not pretty when one comes apart. Seen it, been there, done it.

That's my .02 cents.

It's time for a drink now.

O.K., Thanks for the info. I am using a 75 block. I will be taking the original out and set it aside. I will have the flywheel checked before I put it in. Thanks Again, and, SAVE THE WAVE

If you have the small FW-10.5" and you want to go to the large FW-11" and use your Center Force set up you will have to get a new bell housing,also check to see if your trans has the correct input shaft to match your clutch disc

Thanks, I will have to do some research and decide what I will do. Greatly Appreciated!