sorry I'm still new to building my own engine etc. Im trying to buy the parts to get my heads built slowly since money is an issue. I know the bigger valves are available for these heads but should I go with the stock size 1.875 and 1.562? Its going to be in a mild build that I will drive on the road around 400hp ish. I've heard that there are some issues that need to be considered in order to use the bigger valves. I've found the stock size Sealed Power valves all 16 for around 100 bucks. What else should I get for these heads besides the springs and rockers? Sorry for the newbie questions

 

check out the home porting thread on the racing and performance section. it covers many very good pros and cons.

 

If you're truly looking for 400hp then you'll need to do at least a real good cleanup on the bowls and ports. On top of that filling the crossovers and welding up the center dividers is a must as well.
But that's only after you make sure the guides, seats and surfaces don't require any additional work.
I know this is a do as you save project, but you may want to take a pencil to it first. You have the option of going with aluminum heads, which would require additional pieces and milling, to make your goal much easier to reach.

Jmo

 

If you truly want 400HP from a 350 Olds that is not a mild build. I happen to have a completely built set of #5 heads that I used for one summer, I spent $1100 on them, I'd sell them for $400 plus shipping.

 

That is tempting. What has been done to them and what size valves, springs, etc..Any Pictures? I wonder how much shipping would be to 08081

 

Those heads will easily accept 2.072/1.625 valve combination and it'll really wake up from the size increase. I'd start with Milodon valvesxand gave their 1.710 exhaust valve turned down to the 1.625 head diameter.

 

Has anyone ever used the Lunati roller rocker arms 85410lun ? Ive found them on sale for a great price. They would be for the num 5 head build.

 

Only if you're going to use a 7/16 rocker stud, are you?

 

I dont know. Should I not? Sorrry I'm a newbie

 

Going with a 7/16 stud mount rocjer is an excellent idea. But now your talking more money into your heads to drill & tap the 16 rocker mount holes which puts you all the closer to costing the same as you would have in a set of ProComps which would save you a ton of hassle and provide better results.

 

What's considered a "great price" on those rockers?

 

$150

 

oh well I just ordered them like I said for the price I couldnt refuse. Lunati has a closeout sale on them for 150 plus shipping. If anyone is interested they are available at that price by phone only untill sold out