should i down down grade my heads and cam or just cam??

Ok I have a
383
10.5 compressions
Fuelie heads 64cc .202 int .160 exh ported a good amount but unsure what they flow.
6.0 rods
Cam lift .520 int .540 exh dur @ .50 int 236 exh 242 lob Sep 110.

Wanting to put this in a 4x4 and don't need the extra hp it has now but want more toque and possible mileage.

What would the best thing to do? change heads to a set of vortec heads with a mild cam? Or would I get the same results by just getting a mild cam and keeping the heads I have?  

mruser welcome aboard:

Your second choice is the way I would go. You didn't mention what you had for carb.

Anyway change the cam and lifters first, Comp/Cam has a couple good cams for your 4X4.
Comp/Cam P/N 12-231-2 Grind #X425oH .208/.214 duration @ .050
.432/.453 lift  600 to 4600RPM Good Low End Torque for 4X4

Comp/Cam P/N 12-235-2 Grind #X4254H .210/.218 duration @ .050
.447/.462 lift 1000 to 5200RPM Good Low End Torque for 4X4.

I don't know how much valve spring pressure you have on your big heads,but judging by the specs of your old cam it has to be quit a bit. So you may want to consider a Comp/Cam and lifter kit.

I don't know what rear gear the 4X4 has I would use that as a limiting factor. But it's up to you. But replace the lifters with that new cam, and follow Comp/Cams break-in procedure. It's always been an important factor, but today with the lack of ZZDP in our engine oils, if your keeping your engine for along time I would look into using a hydraulic roller cam.  

These are my suggestions as you asked for....What you do is up to you.  

Bob  

+1, i agree Bob.  those cams would work great for the intendead purpose.  the cam swap will move the torque where you want it, down low.   leave the heads alone for now.  see if you like the way it performs after the cam swap.  

mm well I'm runing a edelbrock 750 and I am not sure of the valve spring pressure i have.
so you don't think that i would have to much head or compression for a smaller 4x4 cam?
the 4x4 its going in has 35" tires with .411 gear ratio.  

The thing to be concerned about is the valve spring pressure. You don't want too much for the cam change. The carb will probably be too big also.

1.Use the valve springs recommended for the replacement cam.

2.You can run the Edelbrock 750,but I think you'll be wasting gas.

3.I think the 35" tall tires with the 4:11 rear gear will be okay. You will probably wind up with a 3:70 or so.

4.Unless you want to purchase a complete Edelbrock Kit. For the top of your engine....  

Welcome to Super Chevy mruser:

Their are 2 different top end kits from Edelbrock for your Small block. I don't know if that maybe a better way for you to go.You can look them up. With the cost of replacing a cam, heads, carburator,timing chain, and all the gaskets. Of course that's up to you, and your budget.

1.P/N 2097-A 435 Horse Power 435LBSFT of torque

2.P/n 2098 410 Horse Power 408LBS.FT of torque

Bob  

well it sounds like i'm going to have to find out what my spring pressure is. didn't think it would have made that big of deal sense I had a full roller set up and going to a smaller lift cam.  

mruser:

You can get a set of Z28 Valve springs for any of those cams for under a $100.00.

Then whatever you need for a shim kit. Be safe not sorry later.....You should not need any machining with a stock O.D. diameter valve springs...

Bob  

ok so i found my paper work from when I had my head work done.
looks like the springs are rv 9903
installed hight 1.850 @ 120
at 1.350 @ 340
coil bind 1.070.
.7850" off coil bind

sorry for the late respons and thanks again for all the help  

Have you considered putting the motor in the truck to see how it performs and then make changes as needed? Might save some money and guessing. JMHO  

Yeah I considered it and still might but I was trying to get more torque and possible better gas mileage .so I'm Looking at my options and getting advice/opinions .  

For more torque, find cam with 15-20* less duration @ .050.  For better mileage, get an overdrive transmission or use less gear. Gearing really depends on use, mud truck or street truck.  

so you don't think I am going to have to much spring pressure
to down size my cam?  

You should always use the manufacturer suggested spring for any cam you get. If you make a small change in cam size you may be able to get away with the springs you have now but the cam manufacturer may not warranty the cam. To use the springs you have now, you have to know their seated pressure, open pressure, and coil bind height, then match a smaller cam to those parameters.