Imco Thumper power? are they any good Ive never heard of them, what are they worth? I found a set never used new in box, was thinking about them for my 502

thanks

Couldn`t hurt maybe a little more sound and less money in your pocket

IMCO's "Thumper" series exhaust manifolds are very similar to their upgrade "Power Flows". The "Thumpers" are primarily meant for replacement of stock cast iron manifolds at a more affordable price point. If you're 502 is basically stock, the "Thumper" series would be the way to good and you will see some modest performance/power improvement over stock cast iron manifolds.

thanks guys, however they only come with standard risers, and on the web site they don't offer a alt, not sure if i can buy a set for the powerflow if they bolt right up, I would think they do. but unsure.

Correct about them being a replacements piece with a a bit more flow.

IF your old iron manifolds are leaking or bad, youll pick up some ponies and lose some weight bolting these on.

The power flows are a notch up- and have larger inner diameter runners and move more volume, power flows are a great high perf manifold for all but the wildest configurations.


UD

I have them, don't expect any more HP but they are lighter and cheaper than cast iron. I really noticed a difference in how my boat comes on plane and rides with less weight on the rear.

Can Powerflows be a direct replacement for merc-gils

is your power steering pump up by the valve cover on your motor????

reason i ask is i put Imco power flows on mine last year and the 90 degree hard line that comes out of the back of the pump hit the manifold.... after doing some research i see that they make a bracket to relocate the PS pump and alternator to fix this issue ($150ish)...... would have been nice to know before every thing was installed that this might be needed....

anyway by the time i bought that relocate bracket, and then bought the brackets to mount my thunderbolt module and shift plate assembly on the other side i ended up with about and extra $200 in parts i wasnt expecting.

hmm not sure until the boat gets home