I wouldn't waste my money on the smog 360.
We scrapped those back in the 80's. lol
We built 383's for small block killers and 440's for big block killers.
Something about big bores that gets me going.:D
I always found funny if someone came out with an aftermarket heavy duty 4.25" bore sbm people would trip over themselves to buy one but over look 383 which is basically one.