Which flywheel do I need?

[Chillin014]

I'm doing a manual transmission swap in my El Camino. The transmission and bellhousing are out of a 91 Camaro RS, it is a borg warner World Class T5. I will be using the hydraulic clutch set-up. I realize there are a few different types of flywheels, 153 or 168 tooth and one of each for one piece and two piece rear main seal motors.

I've got an old GoodWrench 350 Crate Engine in my car but I cant tell what the production date is to figure out which flywheel bolt pattern I need. I do know it is a 2 piece rear main seal but...which tooth count and bolt pattern should I be going for? As far as I've read it sounds like they tried to keep the crate motors close to Gen 1 SBC specs.

 

[Clutch_Grabwell]

You need a 153 tooth flywheel for an '83-'86 V-8 and T-5 equipped Camaro. If you're right about the rear seal this one will fit.
1987 was the first year for the one-piece RMS.

 

[pontiacgp]

if it's a two piece rear seal then the engine is probably internally balanced but I did say probably so you'll have to check that to see if you need a balanced flywheel or not...

 

[anakputa]

I'm doing the same thing right now. Have to make sure its internally balanced or externally balanced engine even though you have the one piece seal. Gasoline/Carbureted engine is internally balanced and Fuel Injected is externally balanced with the one piece seal. I had to get the Externally Balanced.. Schucks/Oreilly sell them cheap if you have a core

 

[Chillin014]

how am i going to check if its internally balanced or not? Also, it's a 2 piece rear main seal to those who are saying otherwise.

I dont know waht year the crate engine was produced...

 

[anakputa]

Is the motor in the car?

 

[Clutch_Grabwell]

how am i going to check if its internally balanced or not? Also, it's a 2 piece rear main seal to those who are saying otherwise.
I dont know waht year the crate engine was produced...

The only 'externally' balanced SBC crank was the 400. The later one-piece RMS motors have very small counterweights on their flexplates and flywheels but are still considered to be internally balanced. If your motor is a two-piece RMS 350 the flywheel I described above will work.

 

[pontiacgp]

it's easy to tell if you need a weighted or neutral balanced flywheel or flexplate....if there is a counter weight on the end of the crankshaft outside of the oil pan then you use a neutral balanced flywheel or flexplate... if there is no counter weight then you use a weighted flywheel or flexplate...all cranks are internally balanced the same and they either need the counter weight on the end of the crank to balance the crank or a weighted flywheel or flexplate...the weighted flywheel and flexplate are said to be external balancing of the crank but by definition the counter weight on the crank is also externally balancing the crank

on a 400 tho the weight is heavier on the flywheel and flexplate and there is also a weight on the harmonic balancer as it's crank was the only crank that was really externally balanced

 

[anakputa]

how am i going to check if its internally balanced or not? Also, it's a 2 piece rear main seal to those who are saying otherwise.
I dont know waht year the crate engine was produced...

The only 'externally' balanced SBC crank was the 400. The later one-piece RMS motors have very small counterweights on their flexplates and flywheels but are still considered to be internally balanced. If your motor is a two-piece RMS 350 the flywheel I described above will work.

My 87 Chevy 350 engine is externally balanced..

 

[pontiacgp]

how am i going to check if its internally balanced or not? Also, it's a 2 piece rear main seal to those who are saying otherwise.
I dont know waht year the crate engine was produced...

The only 'externally' balanced SBC crank was the 400. The later one-piece RMS motors have very small counterweights on their flexplates and flywheels but are still considered to be internally balanced. If your motor is a two-piece RMS 350 the flywheel I described above will work.

My 87 Chevy 350 engine is externally balanced..

the weight you have on your flexplate is the counter balance for a crank that is internally balanced...