Too me it seems like with what I understand (post a video, or audio of the "burp") given everything else (as suggested plug wires, are they carbon, solid wire, age?) It wouldn't be a big issue to pull the intake, check for leaks, also the carb. I've had probably 2 dozen leaking carb base gaskets in my past.

 

The plug wires are brand new think they are carbon and new base gaskets. You talking about leaks in the intake? And now i lost spark to the damn thing. Getting pretty frustrated with it, the motor itself me and my partner we tore it down hoaned it new Rod bearings,pistons rings lifters ect. Havent got the damn thing to run long enough to dial anything in, “ im pretty sure i messed up when putting pistons in and used assebly lube, its hard to turn engine over by hand with no plugs- should i pull pistons back out and just use motor oil- hetting ready to throw in the towel im so frustrated
​​​​​​ Thanks guys for input

 

You should be able to turn it with resistance plugs out. You did use assymbley lube, and oil on the rings?

 

so i decided to pull motor back out and tear back down, I’m glad i did had two pistons on each side in backwards, and when i drained oil was lots of gas in oil, got engine almost ready to fire up.. gotta finish my homemade engine cradle, so i can dial it in before i stab it back in ...!! I’ll post pictures when cradle when complete

 

Will like to see what you come up with as I've been thinking about doing the same thing.