What head work would i need to do to my stock heads to handle .495 lift on both intake and exhaust?

 

Anyone?

 

Depends on springs, and head. Might need to maching the top surface for spring cups, & maybe even the top of the guides if there is a clearance issue with the retainers.

 

Camshafts with more than 0.475" lift require machining valve guide bosses and checking valve seal to valve spring retainer clearance...

 

manely screw in studs, springs and retainers on stock heads will allow .525 lift of stock lb9 and l98 heads had the machine shop check to verify the lift.... i have these parts on my l98 heads in order to run the gm hotcam.. been running this setup for almost three years with no problems.... i will get part numbers for you shortly.....

 

Oh ok thanks, do you happen to remember around how much they charge since im thinking if they charge alot i might as well just save up for some aftermarket heads

 

You could always go with a longer valve stem. I mean its not the ideal way of doing it but it will work.

They also make different valve spring caps and retainers to allow higher lift.

 

Longer valve stem is THE ideal way to increase clearance but is .... somewhat invasive.

Offset keepers is another common technique. .050" offset, along with springs that have a high enough seat pressure, small enough wire to have plenty of clearance before coil bind, and a low enough rate, should get you there easily without having to machine the heads.

 

Comp 981-16 springs and newer chevy 4.3L v6 retainers will give you just up to .500 lift.

 

So if i just change the springs only would it handle the lift im wanting its because im not wanting to spend over $300 to make my heads to be able to hold the lift when with $500 i could buy a set of used heads that already handle the lift.

 

Springs only, probably not; the retainers will likely smack into the top of th eguides.

Springs + retainers + offset keepers to match + careful setup with a spring mic, probably so.

 

Oh and for that kind of work i would have to take it to a machine shop then?

 

Not really.

Buy the spring mic and a pack of shims, and springs (the 981s referred to above would be fine), and whoever's suitable retainers & keepers; doesn't too much matter whose, as long as you can be SURE they match. Do the labor yourself. That's how you keep it under $300, and have a tool to put in your box to boot, for the next time. Might as well also get some new valve guide seals in there while you have all that apart.

 

All of that whould run you right around $300 - $350 if you do your labor yourself and look around for the best prices. I know a set of assorted shims from autozone (comp cams brand) run about $20, I bought telescoping gauges from sears for $40, you will obviously need head gaskets $70, intake gaskets $20, New valve springs $80, retainers $60, valve springs caps $50, valve stem seals $10. So you shouldn't break the bank buy doing it this way.

You can rent the valve spring compressor from a number of parts stores.

 

this is what i had to buy in order for 520 lift

MAN-42106-16 screw in studs
MAN-23652-16 Retainers
MAN-22410-16 springs

i did all this plus installation then had the heads checked and a valve job.... it was around 600 for all this plus to recondition the head back to new... honestly your halfway there to excellent aluminum heads... if i had to do it over again i would have gone with the aftermarket head route..... not worth the money to have stock crappy heads reconditioned and trying to handle a lift of a cam thats not going to take full advantage of it.... if you think about it your really hurting yourself in the long run... i had to learn the hardway...

 

Yeah thats what im starting to think of now just save for some pro comp aluminum heads. I know there not the best but i think they are better then my stock heads for sure and they cost $600 new and assembled.