Am I the only one that doesn't already do this routinely?

While reassembling the LT1 in my cold garage, I found that it was a pain to get the heads to go down over the alignment pins and was also having a bear of a time getting the header bolts to go in without running the risk of cross threading them in the head. After I heated up the heads with a small space heater (warm, not hot), they dropped right on. With the header (SLP stainless shorties), I put one bolt in then heated the header until it was warm with a heat gun - the other bolts went right in. No cussing.

I wouldn't have thought that heat expansion would be that much of an issue, but apparently it is. Happy wrenching.

 

I had the exact same experience with heads and SLP shortys about a month
ago. I did not heat anything up though, just carefully pushed the heads down
on the pins and snugged down the center bolts and carefully threaded the
breslins into the exhaust flanges.

 

I used to have the SLP shorty headers, you have to be careful when putting them on the heads, as things are tight.

 

Yeah it sucks, I did my entire head/cam swap in a cold garage.