We raced a 400 inch Hemi in A/SM back in the late 70’s with a Rat Roaster single four barrel and 850.
Every time we cracked the throttle the lid would deform from the vacuum.
Eventually cracked the lid.
Makes me think that carb was a little too small for that engine.
Went a 133 mph at 3400 pounds on 10.5” tire but we couldn’t get it to stick - only went 10.30’s.
The lid I have was made from a 1-1/4 thick piece then milled inside to 3/8 thick. Feels very substantial, plus the bottom has 3 bolt bosses in the center that the lid could be attached also. Like I said the bottom was a later setup for the single four with the cast in dams. I have a milled 4150 carb that’s supposed to flow 900 but it wouldn’t work on my 499 Indy head engine, had to use a 4500 (7320)
