Opinion - BB Head Experts
Thread Starter
Melting Slicks
Joined: Mar 2004
Posts: 3,472
Likes: 18
From: Lake Ozark, MO
Opinion - BB Head Experts
I have a set of nice oval port (702) 427 heads. They are completely reworked and ready to go back on the car. Here's where I need some help or a sanity check...My valves are currently 2.06 / 1.72. Desk top Dyno shows that with my particular engine build (cam, headers, carb, etc.) I will gain about 25 - 35 HP by having bigger valves (2.19 / 1.88) installed.
Is it worth doing? Machine shop work and new valves will cost about $350.00. The machine shop guy says - don't bother. I think there is a pretty significant gain in flow and subsequent HP.
Would you spend the money?
Is it worth doing? Machine shop work and new valves will cost about $350.00. The machine shop guy says - don't bother. I think there is a pretty significant gain in flow and subsequent HP.
Would you spend the money?
Team Owner
Joined: Feb 1999
Posts: 34,454
Likes: 665
From: Republic of Texas
That's a tough call. Though for what it's worth I know guys w/ 350's that have bigger valves than you have. 
Personally I wouldn't bother, I'd take that money and put it towards a new set of performance heads. In the meantime enjoy the vette.
Personally I wouldn't bother, I'd take that money and put it towards a new set of performance heads. In the meantime enjoy the vette.
Race Director
Joined: Dec 1999
Posts: 11,096
Likes: 990
From: Sierra Foothills CA
It IS a tough call. I can only speak for myself- if I had no plans to get new heads I'd have the bigger valves installed. I always look for a way to max out my combo because I don't like having to wonder how much better it could have run. Those valves will make a difference especially if you have an aggressive cam, good intake set up, & good exhaust. If you don't feel like spending the $350 then just forget about it & don't look back. 
Thread Starter
Melting Slicks
Joined: Mar 2004
Posts: 3,472
Likes: 18
From: Lake Ozark, MO
I tend to lean toward getting the larger valves installed -- so I don't keep trying to second guess myself. All the flow charts show bigger improvements.....If I didn't plan on trying to run a more radical cam, I could probably get by with less flow. I guess $350.00 for 20 or 30 HP isn't such a bad deal. Wish I would have done this when I first had the hweads reworked ,,,,,,,
