ok, rebuilding my 383.
I had the whole rotating assembly internally ballanced by Jim Cook Performance.
the set came with moly rings. i had a performance shop do the lower engine for me and the guy said i needed file cut rings (this all was two years ago).
well, my rings on several cylinders never seated right and i am in the process of re ringing the pistons. what is the difference between moly rings and file cut rings and which is recommended. price is not an issue because i want the best for my motor.
ok, bearings. how do you know the difference between a large journal or not? i know how to do all the measurements that are required, but how do i know what kind of main and rod bearings to get? i think the crank need chamferred bearings.??
I am pretty sure the LT1s were large journal brgs?
i am in no hurry of rebuilding the motor. with the money i got stuck into it, i will take my time and do it all myself. the only reason why i had a machine shop do it is because at the time, submarine service had pretty crummy work hours. ahh, is good to be a civilian now!
sorry for the long post.
just looking for comments and reccomendations.
thanks all!
Lee
96Z 383

 

Any good set of rings should be filed to fit. Moly rings are good, Plasma Moly Rings are a little better. Most engine shops prefer a Moly top ring, with a cast second and a low tension chrome oil ring. Hastings, JE Pistons, and Speedpro are all good chioces. You also need to make sure that the ring end gap is correct for you application. There should be a formula provided with your pistons to figure this out. Or you will need to contact the manufacturer to get this info. If you use nitrous the top ring will get a bigger end gap and if not its a little smaller. There is also a realationship to the bore size as well. you'll have to do a little research at the different manufacturers websites.

As for bearings, you need to determine if you crank has been undersized. All lt1s are large journal blocks. The small journals are the early 265,283, and 327's, and we're talking real early. I don't know the crank pin measurements right off the top of my head but I am sure someone can get this info to you, if not check out www.mortec.com

 

thanks for your help! what i got from you is very useful. i will do some more research too and see what i can get.
thanks again.
Lee
96Z 383