Trick Flo 175 valve size question?

[gregaba]

Anyone know why Trick flo power port 175 heads use a 1.625 exhaust valve instead of the stock 1.65?
I was thinking of ordering a set of bare heads to upgrade from the Aluminum ones I have but noticed the smaller exhaust valve size.
I just got in a new order of SI stainless valves and they are !.65 on the exhaust. Would hate to have to spend the money for a new set of exhaust's.
Summit part # TFS-5641B701-CW
Greg

[blykins]

Probably because it's a relationship between the valve size and the throat size.  The ports are pretty small on the TFS stuff.

You will need different length valves as well, they are not normal FE length. 

[gregaba]

Thanks Brent
I was thinking about buying these heads before I ordered the pistons we talked about the other day but I hate to have to order [I am cheap] new valves etc. to do that.
I know they make power because I read your post about the road race motor you dynoed and it didn't lack for power.
Thanks for clearing this up for me.
Greg