Loop engine cooling vs deflectors/cross flows
Frank:
Its amazing how much cooler loop engines run in comparison to deflector engines. With deflectors it was a massive piston crowns getting heat soaked and massive cooling to go with them to cool them. With Loop Flatheads the loop technology is inherently cooler running and you use the cool running characteristics of methanol, water passages got smaller so it did warm up a bit but loop in no way needed the cooling of a padded deflector Alky. That is why some passages are not there on your NOS Flathead and why water outlet holes are oh so small.
The T ported exhausts are of a concern being so wide at the top also got exhaust gases out so fast but be aware that square high tension rings and wide ports do not go together necessarily and those rings might just deform into the wide ports which means your might need a NOS set of Quincy pistons with single "L" Dykes rings as they were specifically designed to handle wide ports technologies as well as handle easier starting through their pressure back features of operation. Once the exhaust goes out the top of that port the pressure goes slack on the "L" ring and the chances of it snagging a port stop. Not so with a full constant tension square or rectangular ring. Chrome rings are not forgiving. So be aware as you might find a problem the first time you rope it assembled with those squarish ringed pistons. Radiusing the ports does help using those pistons and rings but how much only rotating it assembled after that is done will tell you if you have a ring snagging ports problem. That is why there was quite some evolution going on even in Quincy Flatheads.
The blocks I rebuilt were all helicoiled already, bolted not studded
Frank:
All the Quincy Flatheads I did were all helicoiled already in the bolt holes. Grade 8 Allen bolts or fine thread anodized Grade 8 cap bolts were in use. Those are available at small aircraft and quality automotive parts distributors or specialty suppliers of nuts and bolts. I like the anodized cap bolts because of their finish, their strength and with the wider head with a anodized hardened washer under it spread the torque down over a wider surface than Allan bolts which also come in different finishes and coatings too. A lot of Quincy engines used nearly all Allen bolts all over too for clearancing and standardization reasons. You may have to trim lengths too in the final assembly.