Michael D. Callahan wrote:

Never weighed the NA exhaust manifold, but the turbo manifold weighs 10
    

lbs.

    Stock NA manifold is HEAVY! Probably over 50lbs. I will try to weigh one
tomorrow and report back..... if I still have it in the shop. Should not
even be considered for an aviation conversion.
    It's built to withstand the heat of the air injection reactor system.
Basically, they inject air into the manifold via the vane-type air pump. It
afterburns the exhaust gasses in the exhaust manifold to clean up emissions.
Mike C.

  

You are wrong on that one Mike C.

I've flown the stock exhaust manifold for 5 years now. It does "feel" heavy, but 50 lbs. it is not!
As Paul Conner just wrote, it weighs 12 lbs. I never bothered to weigh it so I did not have a number to share.

It's bulletproof and not bound to break apart and go through my prop, that's why I like it.

Perry