bolt pattern power brake booster

[mopar440bbody]

hey i need to order a replacement booster i would like to make sure i get correct one. should the firewall bolt pattern be the same master cylinder. 3 3/8 x 3 3/8. i my can measure it from inside but its very thigh and awkward . i think i have a 7 inch dual booster from speedway motors . was on car when purchased. thanks

 

[C-440-300]

hey i need to order a replacement booster i would like to make sure i get correct one. should the firewall bolt pattern be the same master cylinder. 3 3/8 x 3 3/8. i my can measure it from inside but its very thigh and awkward . i think i have a 7 inch dual booster from speedway motors . was on car when purchased. thanks

Hi, mopar440bbody,
Did you get your answer?