what is the best way to install the headers on a 70 coupe w 302 ..the engine is currently out cause i had it rebuilt so should i put it in then install the headers or put the headers on then drop the engine and trans in all together......the headers are a set of hedman longtubes 1 5/8 tubes with 3" collectors by the way.....my other question is what size exhaust should i run....thanks for all the info

 

put them on the engine then drop it in

 

its easier to put the motor in then bring them up from underneath.But if itll clear EVERYTHING just fine go for it.