Swapped heater cores on my 89 camaro today in under an hour. Everyone tells me you have to pull the dahboard to do it... thats BS.

disconnect hoses to heater core under hood
Pull dash pad off
Remove Passenger speaker bracket (leaving speaker attached)
unplug and remove ECM
remove 4 7mm screws around heater box cover
remove 4 7mm screws holding heater core assembly to the box
remove heater core assembly from vehicle
remove 3 7mm bolts holdgin heater core retaining brackets
install new heater core assembly into vehicle
assemble in reverse order.

It's just that easy....

-Jim

 

i didnt even unplug my ECU or remove it when i changed out my heater core in my 83

 

yea on these cars its easy.

same year S10 trucks on the other hand...

 

I don't even remove the dashpad or speaker - just reach up in there and get that last screw by feel - but I do remove the ECM to get the extra room for my hand and rachet.