I have been following along...and have some suggestions....
1/ Back to the shop that did the work, especially the head work....the remaining pressed in studs will most likely work their way out...symptomatic of too hot a cook when the heads were tanked...the press in studs need to be all removed and the stands machined for screw in studs...pinning them and or set screwing them will just weaken the stand...
2/ Make sure the push rods are not bent...
3/ Make sure the valve springs have not collapsed ...
4/ Make sure the valve stem seals have not collapsed...some shops just use umbrella style seals, rather than fixed style. This could be the smoke when taking off after idle...
5/ The cam lobe and that lifter could also be damaged from the lack of lifter contact pressure...the lifter is kept in contact with the cam by light pressure from the valve spring and the internal valving inside the lifter...
6/ Also the oil pump needs to be checked for metal contamination...
Personally, I would be pulling the engine and replacing the heads with an aftermarket set of alloys...use studs instead of head bolts and replace the cam and lifter set ....
