will 1986 and up heads,water pump,timing chain and intake fit on a 1999 vortec 350

 

Yes.

 

Be careful on the timing chain, a thick double roller most likely wont fit, it wouldnt on my 97 truck motor. I had to get a high dollar HP single roller from scoggins dickey. I think it is the same from the LT1's

 

Good catch. I didn't read carefully enough and missed the timing chain that was sneaked into the list.

'86 has the older flat-tappet cam type timing set. It's the gear that's primarily different from the '97 roller-lifter cam type set-up.