So ive come across some Vortec heads for cheap and im interested to get them. What Casting #'s should I be looking for, intake, springs for my combo? What else do I need? Should I get them machined?

Would my Hooker super comp headers fit?

How much HP gain over double hump heads?

My combo is:
-357
-10 to 1 compression
-Comp cams Xtreme energy cam 12-262-4
-Edelbrock performer Rpm air gap intake
-650 Holley vacuum secondary
-1.5 rockers
-2500 stall Hughes torque converter
-Hooker Super Comp Headers 3 in.
-Hooker Y-pipe 3-2.5 in.
-Custom 2.5 exhaust, small cat, y-pipe to 2, 10" glasspacks rear.

 

You will be borderline on lift with your cam and stock springs but I think you will be ok. I ran 465 lift cam on stock vortecs for years with no problems. I would get them checked out at a good machine shop if they are used. You will have a pretty peppy engine with this combo and yes probably 20+ HP over the camelhumps unless they've had lots of work done to them

 

i just swapped a set of unmolested 906 castings off a 97 Tahoe onto my Camaro a few weeks ago. i checked the retainer to seal clearance with a caliper, and the tightest one was in the .540 range- which means that any cam smaller than that much lift wouldn't have problems..

if you have a roller cam block, then the HOT cam kit from GM (part # 12480002) is the cam you want. runs like a stocker off idle, then pulls like a beast from 3500-7000. you might find cams that make better peak power, but none will probably come close to the overall powerband of this cam- because it was engineered by GM Powertrain engineers for installation in the LT4 Corvettes in 96, but they couldn't get emissions numbers where they needed to be so they put a smaller cam in them..

for the intake, i run an Edelbrock Performer Vortec (2116) because it's the only one that mounts a quadrajet, but if you are a Holley guy for some reason then an Edelbrock RPM air gap (7516) is probably the way to go..

 

I have stock Lt1 springs.

I don't have a roller block, I have a flat tappet cam now.
I have an rpm airgap so I would probably stick with it and get another.

Right now im running around 6 seconds to 60. With very little traction.

 

Vortec heads last 3 digits of casting # 062 or 906.

They will pick up 30-40 HP easy over the double hump heads.

Stock springs are trash.. Replace them with these http://www.competitionproducts.com/H.../#.Va3RuKRViko

Your valve lift does not require machining of the heads. At .464/.470" lift you are a touch under the guide/seal to retainer clearance limits.

Yes your headers will swap over and work just fine on the vortec heads.

You will need a vortec style intake of course.

Also you will need 5/16" dia intake bolts rather than the 3/8" dia ones like you use now.

Use fel pro MS9800T intake gasket set