Specially for $400.

 

are there any seriel numbers on the heads to look up to see what kind they are?

 

Yes, remove the valve covers, the numbers are cast on the top of the head: Chevy Small Block Cylinder Head Codes - Chevy Camaro

 

sorry for all the stupid questions. but how bad would a stock 350 intake choke my 383?

 

There's no difference between the 350 intake and a 383 intake. There is a difference between stock and a good aftermarket. Again, it depends on what cam, pistons, etc. you use to determine if it will run good with a stock. Most all small block Chevys will run better with an aftermarket intake.

 

Did this motor come with the harmonic balancer and the flexplate?

 

^^^ excellent point^^^

 

I had a 74 Nova with a 383. Had good power and torque. Running a Weiand single plane and 1.94 heads. Blew the thing three weeks after I bought it (I did not do the build it came like that). I found a 350 2bolt block for the right price and just swapped the entire top end over. It was bored .030 and had a double roller. The 2bolt actually made more power with the same parts and was much cheaper. The only thing I do not know was the lift or duration of the cams in either one. Again depends on what parts you have to support the displacement.