i have a set of L-98 heads, casting #083 that i am going to port and polish myself. My question is how much of an advantage is there to upgrade from 1.94, 1.5 valves to 2.02, 1.6 valves? Will there be a sizeable difference in flow, to justify the cost of sending them to a shop to have them cut, if i just have a home port and polish on my heads or do i need a professional port and polish done to reach larger flow numbers.
Thanks,
Dane

 

I am pretty sure the L98 heads don't come with 1.94 and 1.55 valves stock. I could be wrong. Anyways, upgrading to bigger valves can be benificial if you have the right combo of parts. You won;t see much gain if you have a crappy intake and small cam. What does your future set-up look like.

 

i could be wrong about the sizes but i am pretty sure. my set up is a stealth ram intake, lt4 hot cam and new pistons that bump my compression up to 10 to 1. plus other some other misc. parts, but thats the backbone of the set up.

 

oh come on, you guys have to be able to give me more info than this.

 

Well with the larger valve sizes you could go a bit bigger with the cam. The LT4 hot cam can be maximised with just the 1.94/1.55 valves. I don't know if larger valves will give you much with that cam to be worth the cost. Porting is always good anyway you look at it. Porting and larger valves will allow you to run a larger cam and retain some of your low end power that is typically lost with big cams. The porting will keep intake and exhaust gas velocity up and counteract some of the torque loss you could see if you didn't have good port work.