ProStreet83C10

Hey guys, hopefully theres enough people here to help me out with this. Anyway i currently have a 305 headed 350 in my truck with what i know to be a "3/4" race cam, which to me sounds basically stock, lots and lots of power/tq down low, pooch up top.

Anyway, i got a hold of a free set of vortec style heads today, still need to go and remove em and see what exactly i have but im planning on doing a mild engine build with these and seeing if i can improve over my current set up.

Ive already talked to a machine shop about what id like to do and what itll cost to have the heads gone through etc etc etc. Anyway as far as what id like to do with the build heres what i somewhat have laid out in my head

350 vortec heads with whatever massaging the machine shop can do
Edelbrock performer RPM vortec style intake
Comp Cams xe284h or similar grind cam
Comp Cams roller rockers (1.5? or 1.6?) ratio rockers??
Comp Cams valve springs and pushrods
new timing chain OR possibly gear drive set
Long tube headers
3000 RPM stall converter
possibly a little bigger carb - 700 or 750 cfm

Now, the things i have questions about are as follows

As far as compression i realize the current 305 heads are helping me in that dept but lacking in the flow dept. Ive never been into this engine and have no clue whether im running a stock style dished piston or a flat top piston. Im not opposed at all to going as far as swapping pistons in this build to help in the power dept, but i also dont want to have to do it if im not going to gain much from it. Im obviously all about higher compression, but im not sure where im at right now with 305 heads and dished OR flat top pistons and where id be in going to a vortec head with the same dished or flat top pistons.

Another question i have is in the cam, is the cam im wanting way overkill for the rest of the set up or would it be a pretty decent match, ive already got 4:10 gears and will be adding the other nesc. components as i get into the build, I just dont want to have an over cammed engine that is lacking power.

Lastly, what all is needed to run a vortec style head on the older 010 350 blocks, what is the same, what is different, what is needed to be changed to make the differences work.

Im not really looking for a specific hp number, but im looking for a truck that will FAR out perform what it does now performance wise. Id LIKE to see around 350hp out of this setup, maybe more, but i also dont WANT to spend $5,000 doing it either.

Let me know what you guys think so far, and anything im missing with this info thats considered critical i will add in after a few comments. Just too much going on in my head to be sure i covered it all.

Thanks guys!!

kelsey_canard

iTrader: (6)

I'm actually very interested in what people are going to say for this build.

ProStreet83C10

good deal, hopefully we can get some seasoned guys to throw their .2 in the bowl

hefftone

I am dealing with nearly an identical situation! Except for the budget, pistons upgrade, and automatic transmission! Will be watchoimng closely.

2011grandsport

Need a little more info. What model truck, trans type 350, 400, 700r4 etc.
As for the heads, you need to have them checked out before doing too much due to they may cost you more than they are worth to rebuild. There are alot of aftermarket alum. heads on the market with far better results than the vortec or even the old stock performance heads for alot less money. Unless this machine shop is a peformance shop then you are only going to get the standard work so be careful.
What is the intended use for the truck, DD or weekend worrior, this is where you draw the line for how much is to much.
The answer to the question to run the vortec heads is you just need the correct p/n intake to fit the heads. The heads will fit any of the sbc blocks from the orig. 283 to early 90's 350 just as your existing 305 heads do now.
Here's a list of parts to get roughly 425 hp out of a sbc.

Good flowing vortec head(port work done) 2.02 in. 1.60 ex valves. 64cc combustion chamber. 3-angle valve job.
You can use either dished or flat top pistons. w/4 val. reliefs.
Dish piston w/64cc hd. 9.5-1 comp./lighter in weight
Flat top piston w/64cc hd. 10-1 comp.
Camshaft with .500" to .525" 230 @ .050 duration w/springs,retainers, push rods.
Edelbrock RPM intake should be fine (port matched to head)
1.5 ratio roller rockers/ stay with this ratio.
longtube headers
Have the block deck checked to know how much the piston is recessed. The piston needs to be flush with the top of the block. This will help with your compression ratio.
Use the felpro blue intake and head gaskets, they are the best and if you have a problem there is very little clean up when removed.
Timing chain double roller w/3 keyway crank gear minimum.
Distributor-aftermarket HEI or better designed for performance. Stock HEI's will miss at higher rpm's.
Carb-650 dbl pumper or vacuum secondary's.

For your info, if this is a stock bottom end crank, rods and pistons becareful on the amount of rpm's you turn it to. Stock parts do not live long at high rpm's.(keep it under 6500 rpm's).

Chris.O

Read this article then do even more reading. http://www.superchevy.com/how-to/148-0208-vortec-heads-valve-lift/

You cant stab a big lift cam in an engine with vortec heads. Theres work to be done or choose a smaller cam. The best thing you can do is find out what you want to use the car for, what rpm range you want the power at, what kind of driving characteristics you want/need then call up your favorite cam company and give them the answers to those questions. 350 crank hp is mild even for a stock bottom end 350 and vortec heads so you wont really need to spend much money. Back to that article, you can have the heads machined if you need more lift or contact comp cams about their beehive springs made for those heads. They arent cheap but neither is machine work.

SPDEMON

Well, a 10:1 350 with a comp xe274, trick flow heads, 1.6rr, performance intake manifold (performer rpm or similar) , and a 750 double pumper should net you an honest 425hp. However, in a heavy vehicle, the torque band that a full roller set up provides is kinda nice. But then again, your drive train is set up with a stall and gears....anyway, if you're looking for 350hp with vortec heads, you may achieve that with the set up you described. However, you could achieve that number easily with a good set of heads and a much more efficient camshaft.
So, my vote is quality heads, and an xe 268 or 274 if you're going to stay hydraulic. But also consider a cam with tighter lobe separation for better drive ability and cleaner powerband...