[Rev]

I think that this is ancient history now. 5 years ago there were problems with valve guide failure I think due to the different angles with the "twisted" valve angles. Now they use nothing but bronze valve guides and make specific requirements for proper rocker arms. Also, it's very important to use the correct length push rods.

I did do all that when I installed my TFTW heads. I used TF 1.7 roller rockers (look like Erson to me), bought and used an adjustable push rod to determine correct length and did check valve/piston clearance. All this takes extra time and costs extra money, but I think it's worth it.

BTW, no problems with the TFTW heads in the last year since I've installed them and about .4-.7 seconds off of the 1/4 mile et since then.

Rev