Well i had to put the stock manifolds back on adn one of the bolts will not thread but all others will. Can I be safe to run without one header bolt?

will it leak?

 

Yes, you just might have an exaust leak causing the engine to run a little rich, but if it seals, then dont worry about it

 

its the one on the drivers side that is the third from the front of the car going back

 

you are safe to drive the car, yeah...

it will leak sooner or later.. probably sooner and MAY eventually blow the gasket out (probably not if the car is mostly stock)


I had a few bolts back themselves out, and i was driving it for a day or two before I noticed and put them back in...

if its just 1 you should be fine.