so far on my 98 vortec 350 in my sierra i have bolted on Thorley tri-y headers, k&n filter, full flowmaster true dual with 2.5in tubing and a 160 degree thermo... im looking for power beyond the bolt-ons. My question is should i stick with the cast iron vortec heads but port and polish them, or should i opt for the fully assembled aluminum Edelbrock E-tec 170cc heads, or the same Edelbrock heads in the 200cc version? I will of course change the port match the intake manifold and get a new cam and lifters which i will probably need help with later to match... but stick with the cylinder head question for now... any comments will help!

 

These are nice heads as well. The GMPP Bowtie Vortec smallport heads
http://www.sdpc2000.com/catalog/3129...inder-Head.htm

peace
Hog

 

The factory Vortecs are an awesome design, and just get a good set of valvesprings in them and they will work to applications around 450HP. If your looking to save some money I would stick with the factory vortecs, clean em up a bit but DON'T bother with a porting, I have seen ported heads put out worse numbers than a factory head. I have a machine shop in Orlando that builds the best of the best engines for alot of the guys down there and they say to leave em alone if your not looking for crazy HP numbers. The e-tecs are nice as well as Hog's suggestion, but use the money you save on buying cylinder heads and put toward valve springs, a nice cam, and if your wanting to stay EFI look into getting a marine intake manifold are buying a carb manifold and have it drilled for fuel injectors and fuel rails (you can also buy a complete intake manifold with rails from Accel for like $350 on summitracing.com) and get a adapter from www.intakeelbows.com to use your factory throttle body. And get a good tune. You'll be looking at 400+HP with a good cam selection and tune with the rest of the mods. Your factory intake sucks for doing modifications that net big HP increases, trust me, I know lol. I'm going to carb manifold route here soon. There's alot of info on www.pacificp.com and click on performance forums

 

As far as cleaning up goes, I mean do a normal valve job, you hot tanking etc, normal cylinder head rebuilding stuff. They don't make an intake manifold for our engines that just bolts on and still retains all our efi stuff. You could go carbed if you wanted, or buy the carbed intake, use that elbow adapter, buy the new injectors, and you would then need to rewire your injector harness to plug into your factory one. There is ALOT of info on the pacificp website. You could use a smaller cam, and get some HP out of the factory intake and injectors, but if your looking to make alot of HP your gonna have to do something with that factory EFI setup, because it sucks and you can't upgrade injectors

 

could i use one of these intake manifolds with that intake adapter elbow u mentioned? since its made to fit my truck would i need the elbow?
http://store.summitracing.com/partde...&N=700+150+150
or...
http://store.summitracing.com/partde...5&autoview=sku

 

You could use those, but would need to have them tapped out for injectors and you would need tp purchase fuel rails/injectors as well. Those manifolds are for carbed setups. You would need that adapter.

 

and i can get it tapped for injectors and all that at a local machine/engine shop? what rails and injectors do u recommend? would i have to do nething to my electronics or any wires or is it all just basic bolt up?

 

Yes, your local machine shop can tap the manifold for you. Check out that intake elbows website, they can provide everything you need, from converting the intake manifold, to supplying the needed fuel rails.

 

so i can send my manifold to them instead and theyll do all the work for me... but what besides the EFI intake conversion job would i need to get from them? just the fuel rails? will i need to modify my wiring harnesses or any electronics and will i need new injectors?
(whew... lot of questions... sorry)

 

From them you will want to send teh intake you get to them and have it converted for EFI, purchase the intake elbow adapter, and fuel rails from them. You will then need to purchase injectors from somewhere (I'd look around here for some good stock injectors off the LS1's). You will need to do some wiring to hook up the new injectors and also run new fuel line to your factory lines, oh and a fuel pressure regulator. It's alot of work man. How much power are you looking to make?