Ok, first off I have used the search and 90% of threads say crossover isn't worth changing but here's my dilemma. I bought a boat that already had crossovers with stats. One engine has erratic temps and much higher oil temp and varies between 120-180, the other one runs right about 120-140. Both had 160 stats with no holes. I just cleaned the throttle bodies and installed new iac on both motors. I need to set timing after the motors are up to temp but I can't get it warm at idle. I bought restrictors thinking they could stop hot pockets and build some temp. Good/bad idea?

Motors are 94 502 efi's