I am trying to figure out which head to use my 350 I am building. I am wanting to get about 300-350 HP, enough HP to have fun with a 4 speed behind it. Dilema the 487 heads are completely rebuilt with 5 angle valve job, but since they were built for racing I for go the hardened exhaust seats. they have 2.02/1.60 valves. The 993's need a complete rebuild, so opening them up to 2.02/1.60 is not out of the question. And I want to stay with one of these 2 heads, just for nostalga sake, Yes I am old. I just want to keep it all GM.

Aftermarket heads are on the 400. For those of you that are going to say it. I would agree if I wanted more power out of the 350.

Thanks / Later
Spud

 

Weekend fun car? Only driven a few hours a month? If so, don't worry about valve seat recession- it'll take years for that to happen unless you drive around on the street at 4000 RPMs using unleaded gas, towing a trailer. If you're the nervous type they still make lead substitute in those little bottles that mix with your gas.

 

I hadn't thought about the useage, It most likely will be only on the weekends, and around town driving, with just a few 20+ mile drives a year.

 

I couldn't resist getting in ther and porting the 487's to go along with the big valves and nice 5 angle valve job.
There is way too much to be gained here to leave them stock.
you'll love the way the motor wants to rev up top.
In this case more flow = more fun

The 487 heads will port up real nice. Go for it.

 

I am too chicken , yea you get the idea, I will leave stuff like that to the pro's. And besides its the wifes toy, I can't let her beat me.