I want to get my car into the low 12's and the best it's ran so far is 12.9. I have bone stock GMPP Vortec heads except for guide machining with comp 981 springs (rated to .490 lift). I have an LT4 HOT cam that is currently running 1.5 rockers and I know that GM recommends 1.6. I want to pull my heads off and do the following to them:

cut the seats for 2.02/ 1.60 valves
put springs to handle .525 lift
Pocket port the heads
put screw in studs
elongate the pushrod slots
go from a 1.5 rocker to a 1.6

Is it worth the hassle, what do you guys think it will cost me? Should I just wait and get some E-tec 200's?

 

Don't know if it is worth it but I had SDPC built me a motor with the aluminum FastBurn heads and their TPI base. The FastBurn have all the goodies, trick valves etc. With 21 lb injectors, runners, 52mm, 1:6 roller tip rockers and a modified TPIS PROM from TPIS, in Denver Co. and the GM HotCAm and the car has 345ft/lbs of torque and 245hp at the rear wheels. The car is awsume.

 

I just called my machine shop and they told me the price would be about $330 dollars to get all that work done and that includes the price of the new seals and the 2.02/ 1.60's. I would still have to provide the SPRINGS and the screw in ROCKER STUDS. I would also have to pocket port the heads before I take them to the shop.

Heres another question, What studs do I use for the vortecs with no guidplates. Do I use the GM ones that were on the LT4??

 

i feel it is worth it to do mods to the L31 v-tech heads,i feel that the perfect valve size is 2.00in 156ex due to the design of the combustion chamber but its up to you on that,i use only ARP studs on my engines 3/8 stud for up to 6500 rpm and 7/16 studs for anything above or big block applications,now to the valve springs go as large as you can without exceeding 120 lbs on the seat unless you have retro-fit hydr.rollers or the AFR hydra-rev kit installed,the aluminum edelbrock e-tecs are pretty sweet and all the work you want done is there plus the benifits of aluminum,i believe more power is in the light-weight head...

 

I think that I am going to stick to my heads, but it sounds like it's gonna run me about 750-800 dollars to do the work to them. OUCH!

 

Here's one solution. Get the beehive conical style springs from Comp Cams for your heads. There are two types. The first is cheaper....for your stock 1.25" pockets and taper UP to a 1.48" retainer...about $85 a set. I have this and it works great. The other option goes from a 1.25" pocket and tapers DOWN a smaller retainer...much more expensive but very light weight for spinning up higher before valve float. If you keep your stock springs, you'll go into valve float much earlier when you go to the 1.6'' rocker. So you need to address the spring issue before adding 1.6" rockers.

I would forget the 2.02 X 1.60 and get the Manley Street Flo valves in the stock sizes, they have the turned down stem and the tuliped valve heads. Have them back-cut and have them pocket ported by someone with Vortec experience. I've seen excellent results with this set-up....and it should save you alot of money. You can save on not having to open up the pockets or machining in larger valves+ the mandatory port work involved when you go to a larger valve.