decided to go whole new engine, but pulleys dont match up? which do i use. 390 engine

ok, i was having problems with my engine, (check the bearing thread a couple of posts down). My dad found a guy that was selling a 390 that had just been rebuilt. Thing is that the pulleys dont match up. I dont have power steering or air, so i only need a 1 row pulley. But my old engine had 2 row pulleys on it. Well this new engine has 3 row pulley on the bottom.

Here are the diameters of the pulleys and let me know what you think i should put on:
my old ones: crank pulley was 6&3/4", and waterpump pulley was 7&1/4"
The new ones: Crank: 7&1/4", water pump: 6&5/8"

How much room should be between the two pulleys?

Rebuild your's. Everything matches and bolts up already. And you know the history of the engine.

Why don't you put the original pulleys on the new motor or am I missing something here? You'll need the original water pump etc. for your application so just transfer the whole front motor assembly onto the new 390. Stu

yah id aggree with dacofa, id rebuild yours at least youll know it was rebuilt properly. nothing worse than buying someone elses "rebuilt' and finding it was just a top end and new gaskets. unless you know the person id wouldnt chance it.
My guess is that it will cost you around 1500 to rebuilt that thing top to bottom stock style another 800 or so for performance stuff. If he sells it any cheaper than thers an issue there. hes not just selling the cost of the rebuild but the main components as well , block, heads etc.
Just heard too many issues with a 'just rebuilt engine' going bad.
Good luck either way.

[addsig]