took my pops for a ride in his car today.... yup overheats when driving , cools when stopped. the shroud must not let enough air flow during car movement.

still backfires off idle...

here is a plug, they all look like this.

I don't have much room for a fan, id love to put in flex fan, but I just don't know if it will fit. I have 3" total from the face of my water pump to the face of the radiator. seems like a 383 in a big ol' B body would have more room?