I am going to be building a new motor and was wondering if painting an aluminum block would be ok. From what I understand the iron blocks are painted just to prevent corrosion. Would painting an aluminum block cause it to retain heat or anything that would be bad for the motor? I want to go with an LS7 block because I am trying to keep the weight down, but I may still go with the LSX block.

 

No, painting the block will not hurt anything.

 

i thought about painting my ls3 block, but decided there would be no point in a f-body, you cant really see any of the block when its in the car.