my 1985 mustang streetrod is poping back thru carb. and now no start.can anyone help my stanger?

Question

its a302 motor souped up .with holly750 and msd ciol pak

Answer 1

if you just put the motor together it sounds like you have the distributor 180 out-if this is the case you set your top dead center on the exaust stroke instead of the the firing stroke-hope this helps ya-might also have your rockers tightened down to much-that will leave your valves open and cause it to come back up thru the carb

Answer 2

i need more details to help u

Answer 3

timeing chain....