Eddie 70

I just pulled the heads off of my original engine and was wondering before I go spend the money to get TFS 23 Degree heads. The pistons are flat top with two sets of valve reliefs. The stock compression ratio was 10.25:1.

What kind of compression ratio am I looking at with the TFS heads?

Also is there a place I can get the flow numbers, valve sizes, etc., etc., for the 186 heads?

Thanks for the help.

A C

If I remember right, your heads are 64cc combustion chamber, so if they make the heads with that size chamber, your compression ratio will be the same. Also, your stock heads should have 2.02 and 1.60 valves. I have been looking for stock flow numbers for these heads as well, just to plug into Desktop Dyno.

AC

1979toy

The 186 head flow data that I have from http://www.aros.net/~rbuck/dyno2000/...%20Smallblock/ shows 1.94 / 1.60 valves. It's possible that GM used both sizes of valves with the same casting.

MikeC

Very possible Gm used 2 different sized valves in the same head casting
I know 78's are like that. l-48 are 1.94/1.5 and L-82's are 2.02/1.6

mean8t

Are those the TFS 195cc intake runner head. If they are you can go to http://www.chevyhiperformance.com and look under tech articles then click on "engine". In new window click on "Giant Cylinder-Head Flow-Bench Database; October 1998-May 2001" find the head your looking for. THe only TFS heads I found were the 195's and the twisted wedge. The 186's are not on there but the 492's were and they will be similar. Look at the flow numbers of the Iron Vortec heads and remember that they are about half the cost. Good luck