390 first start and break-in

[faxon7]

I just finished a 360 to 390 conversion and broke in the cam - 2k rpms for 30 minutes.

During the break-in, the temp gauge barely went up 1/3 of the way, and the stat didn't open (couldn't see any movement in the radiator). I checked the stat by boiling it before install, and it opened in boiling water. There was just some light-brownish bubbling in the new radiator, thinking from new radiator sealant? That even bubbled up out of the cap opening after letting off the throttle at the end.

Started out with 2 gallons water in the block and a gallon of coolant and 2 more gallons of water in the radiator. Had the truck hanging out front of garage door, about 65 degrees out, and blew a fan on high up under the radiator onto the block. During the run kept putting a little water in the radiator to keep it up above the fins.

Should I consider that abnormal enough to keep doing more checks on further runs? I was thinking there would be the usual signs of building temperature, but that didn't happen.

Regardless, very pleased to have it back up and running, ready for a drive.

Thanks again, Josh

[BRUTUS_T_HOG]

you check your t-stat by squeezing the upper radiator hose. when it opens you'll feel the hot water being pushed through. your temp gauge might just be reading low