so i got these round port headers 3 into 2....for free but i was wondring would it be a good idea to put them on a square...the dood who gave them to me said he ran them on a square port and it was fine ...so i was wondering if its a good idead. thx

I've never heard of anyone using round port headers on a square port head. I would think they wouldn't match up well and you would have an exhaust leak.

It'd probably fit, but the whole point of headers is to improve flow. Mis-matched port shapes is going to seriously mess up the flow - quite possibly flow worse than the stock manifold. Seems like a step backwards to me.

hmm well the header shows sign that its been used on a square head......but hey i got em for free

Buy it, sale it on ebay and buy a better one

Repaint it, sell it, and buy a square-port header.

IIRC the roundish ports are smaller than the square ones, so you'd be restricting some flow by usin' 'em...

No expert, just sayin'

hmm well the header shows sign that its been used on a square head......but hey i got em for free

So you got it for free. give them to someone that has a P-79 head and get the proper one for your engine. Like Arne said , the idea is to improve the flow not restrict it . If someone gave you a free muffler from a MG would you use it on your Z because it was free. Gary

Hey! No bad mouthing MGs!!

MG's, aren't they those english Fairlady roadster rip-offs.

I'm pretty sure that the MG came first. I know that's off topic but it makes more sense than the question this thread is based on. If you want to put that header on your car, do it. It's your car. It's not right but, it's your car.

I heard the roadster was on sale a couple of months before the MG.

yes, the roundports are SMALLER than the square ports.

soo...... a square header will work ok on a round port head, but not the other way around