The biggest problem I see is the differences in opinion on mechanically sound and taking advise from someone who built there motor and maybe there buddies .some on here have built 100s . When you can take every bolt from motor mix it up in a can and still know where it goes like a dexterity test for mechanics
I get all my parts from Jeff and he hooked me up with cam at redline to cut all my trannies,I personally run a stock cyl fast drag ported bike it's dubbed the cub killer Jeff has been tried and true for me since 05 even at midnight while tuning the day b4 a race
Fast racing has .020 metal base gaskets,and tricked tig is the best option sometimes but that area is so thin I can see it becoming part of the puddle while building it up then hours of machining and grinding for a 150$ set of cases. I'd rather start over lol
You chance distorting that and rolling it over with a tig creating a low spot,marine text is best but metal base and three bond will hold no problem I have put together so many nightmares like that with no call backs,motors running hard for two years or better
First things first,pressure test that motor,check compression,make sure plug caps are good and all electrical checks out,you can chase your tail jetting a motor that has an air leak or electrical issue
Why the cast pistons just curious ?two heat cycles in garage ,ride it hard just don't string it forever ,like 2secs in the band then shift let engine slow itself down
I started by cutting every tube out in the front ,don't be afraid to cut if you know how to weld and fabricate if you can't fab leave it alone it takes a lot of time and brain storming I had about 80hrs into frame mods about 20hrs into pipes starting with raw sand casting and straight stingers I bent it all myself
Everyone's porting is different my dune ports come in at 360-340 main,but I would talk to guy who ported your engine.i know I'm damn close on jetting anything I build
Like I said good ideas bad approach,if those worm holes are not perfect they hurt you and I wouldn't even bother in an 1/8 set up what durations are you running