Does anybody have the facts on which is better? seems EVT decks about .050-.055, IM does less. I believe IM's have bigger valves.
Has anyone flowed either? or both? Alot of EVT's for sale, never seen any used IM's.
post pro's/con's of both.

as a 3rd, what does hoyt do to them? price?

I'd go with EVT since they're decked more!

Do you have to run higher octane fuel with the decked heads?

I have EVT Parts on my motor.
My compression is 179 #'s on each side, and I run 93 octane.


Hope that helps.

EVT can build your heads anyway you want them.... decked or not.... both IM and EVT run the same size valves to my knowledge....

IM is a mass produced head....

EVT and Hoyt are individually built.... you will pay more due to the time spent porting and polishing

I am of course in favor of EVT since I know the time Robert puts into his work... the man is very meticulous. And the fact I run an EVT built engine.

I have had good luck with both but run the IM heads now.

And BTW, the IM heads are not 'mass produced'- they are done by machinists just like the others. They are less expensive due to the total volume the shop handles and in house sourcing of parts, not by less craftsmanship. They do one recipe and do it well.

EVT doesn't charge all that much for the machine work. The valves they use are more expensive which makes the total of the heads a little more if you get everything with them. The machining prices are pretty fair though.

With IM, you are getting their recipe, the way they do it, and you have no input as to what is done. Other than do you want roller rockers and push rods or not?

With the EVT (if not buying used), you can do whatever you like. You can do stock sized valves, or oversized. You can deck them to your liking or let them recommend something for you.

Saveon, it's really about what you want. The prices are pretty similar. If you don't mind used, you can find the EVT heads used pretty cheap. I know duckaholic still has a set for sale. As far as the machine work itself, I'm sure they both do a good job. The EVT heads we had were nice. I liked them a lot. I've never seen the IM's first hand, but trust DB8's opinion on them. At the end of the day, there is not much difference between the two. They are both using stock briggs heads and doing their own thing with em.

thanks all, I'm gona go with duckaholics, seems like a nice setup.

The IM heads were nicely done and it was a quality job.