so , i noticed when i got my gaskets --manifold-- they still had the lil metal pieces covering the rear port holes, .....these the right gaskets for the 86 heads??

for some reson i thought 86 heads used a different flow patern and these were actually open instead of closed....

im prolly wrong though

anything i need to know about before i yank the heads off the 92 and replace them with these 86 and earlier lb9's?????

any mods need to be done other than the intake manifold bolt holes. --done already--

 

The main "flow pattern" is the same. Some 86 and later cars used the rear passages for the heater hose connection. Those restrictors make sure that if the thermostat is closed, equal amounts of water come from each head, rather than one flowing it all and the other flowing none.

Other than that, they make no difference whatsoever, since intakes that don't use that heater connection, don't flow water through the intake back there at all.