ive seen in magizines and catalogs where some products are made for pre 86 or after 86 and my question is whats the difference????? if i can get a response, that would be great. thanks

 

There are a few primary differences.. The biggest is the change to a one piece rear main seal (in 1986).. Post-'86 car engines also started coming with factory roller camshafts along with center-bolt valve covers that seal better then the old perimeter style covers.. Another difference is the center pairs of intake manifold bolts. They are at more of an upright angle on '87-up engines (this is why you see the options on intake manifolds). That sums up the major differences I think.

 

Yup... thats about it... bolt holes are a MAJOR diference. Just ask someone who has had to clearance and older intake for newer style heads, or newer intake for older style heads like me!!!

 

Ok, maybe I should have said that one of the major improvements was the one-piece RMS.

 

so just the intake and the valve covers are the only thing that really matters. because im changing my 91 TPI to a carberated engine and im going to run no emssions.

 

If you are switching to a 2pc RMS you will need the flexplate from the older engine too. Be careful with this though, to make sure it has the same tooth count (ie. size) as your original, otherwise your starter wont work.

 

why do i need a 2 peice RMS or a one peice? or more like whats the difference

 

If you are just changing your intake, you don't need to worry about it... The difference is the seal at the rear of the crankshaft, the one-piece is the newer design and requires the use of appropriate flexplate/flywheels.

 

well im rebuilding the whole engine whats your suggestion

 

That would be to order the correct kit for whatever engine you plan on rebuilding so you get the correct VC gaskets and RMS. Also the newer engine kit will come with intake gaskets with restrictor holes for the rear coolant passages you wont be needing those kinda of POS gaskets.