I have a 350 tbi motor K series from a truck that I am rebuilding.
It's a 1 piece rear 2 bolt main but I have decided to instead since it needs to be bored and the orginal pistons are kinda bad to instead bore the block and clean it and then buy a 383 rotating assembly to put in. The problem I'm running into is I have the option between and external balance or internal balance.

http://www.adperformance.com/index.p...roducts_id=602
External

http://www.adperformance.com/index.p...roducts_id=604
Internal

Which is the option do I need to take?

I have a 700r4.
Thanks Guys!

 

If you can afford it, go with the internal balanced rotating assembly.

Good luck

 

internal as well...

 

Internal..got it! Thanks guys.

Is there any thing special I'll need to do like change the stock flex plate or anything of that nature?

Thanks again guys.

 

whomever is building your short block, should be able to give you the best match for your application... at least that's what I think ... ...

 

That's one of the reasons for going with an internally-balanced kit - so you don't have to do anything special about the stock flex plate or damper.

Whether you need SFI parts is a different story, of course. But, even then the internally balanced parts would be preferred.

(Don't even get started with the "Is a one-piece rear main seal flex plate externally balanced because it has a weight on it?" stuff.)

 

I found for slightly more a complete kit with forged pistons but is externally balanced. But they provide the Harmonic dampener and flex plate. The plate is 168 tooth. I'm assuming I'll need to get a new starter but will the 168 felx plate bolt to the torque converter with out issue? It's a scat crank and probe forged pistons. The rods are brushed and been clearenced for 350 motors. They make a mention about checking the oil pan clearance for some appilications and that a dent may need to be made to the oil pan to let the crank clear.

The pistons are -12 cc dished and I'll be running 58 cc HO heads. What would my compression ratio be with this setup? I've tried to calculate but keep getting weird answers.

Thanks guys!

 

I'm not sure about the pan but the block does need clearanced . Not to sure where I've not done one but i have read alittle about 383's and there is some block work involved.