What is the benifit/HP difference between a 3 angle job and 5 angle job?

I'm getting my heads pressure tested/decked right now, and Tuesday I'm headed back to give them my 2 valves (2.02/1.60) for the Valve job. What should I have them do?

 

From what I've read, the more angles the better flow around the valve. I've seen in a couple of forums that recommend 3 angle is all you need.

http://www.jaytorborg.com/engine_design.htm

Look down the page at cylinder heads.....this is a quote from it....

"By grinding the valves and valves seats at multiple angles, such as a 30 degree top angle, 45 degree middle angle, and 60 degree bottom angle, gas flow will be much smoother. This is called a three-angle valve job and has become the standard of the performance industry. With the right precision equipment, even more angles can be used to further improve flow smoothness, although improvements are minimal beyond three angles."

I have not found any numbers between the two yet.

 

Are these heads stock or ported(if ported by who)

30 degree top cuts are kinda 1970's tech...I have good luck with 37 top, 45 seat, 60 bottom, 75 throat to venturi. If the chamber was ported real flat, then you should buzz a i6 x 15 over the top of the 37.

For the exhaust, you can run a 15 blended to a 30 top, 45 seat and radius bottom if you wish. If a radius cutter is not availible, then cut a 60/75 combo just like the intake.

I am hoping you are not putting 2.02's in stock heads.

Dennis

 

Also, if not already, back-cut the intake valve with a 30.

 

No no no they arent stock heads. Thanks for the info dennis and eric

 

What about Guides? Should I have them yank out the stock ones and insert some aftermarket bronze guides?