im buildin a 383 for my 4x4 84 chevy short bed with 44 inch tires, 700r4 trans,and 6.17 gears. i need this motor to make a good amount of low end power and still rev up to 5000-5500 and im wondering if stock vortec heads, 9.75 compression, lunati voodoo 262 cam, performer rpm manifold and 650 edelbrock carb would be good and still get over 12 mpg. thanks for any information and help.

Matt  

12+ mpg with all that weight, rolling resistance, and gear. That may be a little optimistic. A true 9.75:1 compression ratio on iron heads would also most likely require premium fuel.  

yeah, mileage on that build is way out the window. since its probably a wheelin rig, gas dont matter. unless its a daily driver... ive got a performer manifold if your interested...  

so forget the gas mileage would that be a good motor though? i figured it out that i would be runnin 2000 rpms at 63 mph.  

I had an 86 short box, with a 325hp 355, 700r4, 36in tires and 373 gears, most of the time I got 8 mpg. I dont think you will ever see 12mpg, unless your drafting of a semi.  

2000 rpm is quite a bit of speed for a 383 with economy in mind...

A lot of OE 305/350 cars will turn 1000-1200 rpm while cruising. Sure, a V6 can get away with 2000 rpm cruise with good mileage but the larger engine is giving up mileage by having to fill a physically larger cylinder.

Factor in air resistance from a big, tall ride and rolling resistance from those huge tires and your 2000 "ideal" cruise speed won't go far.  

ok i know im ganna get shitty mileage now. i just want an opinion on wether or not the 383 i have in mind is a good motor to push this truck.  

Depends on your definition of good...

A 383 would probably be better than a 350 as everyone knows it will make more low-end power. I'm not the biggest fan of Voodoo cams, but those issues may have been resolved with Lunati's change of ownership...

I'm a firm believer that Edelbrock carbs leave power on the table compared to modular carbs (Holley and Demon to name a couple).

Vortec heads are vortec heads. They're fine for a 5500 rpm engine.

Good luck on dialing in your 9.75:1 compression that close. You better be taking some careful measurements for that to happen.  

well i have the same cam in my 71 nova 355 with crappy 882 heads and a edelbrock 600 and it runs a honest 270 horse and it has lots torque all across the board which i like. so i figure a vortec 383 with this same cam will have about 350hp and over 420ftlbs of torque im guessing.i havent had any problems with the cam with 8,000 hard drivin miles on it so far.  

Personal experience is a plus...

The fact that will you limit RPM's can probably allow you to use less spring pressure, or live with the conservative springs that Lunati prescribes for the Voodoos.  

im running the lt1 z28 springs 310lbs open pressure in the nova. i thought about the 262 xtreme 4x4 cam from comp but it seems to be just like the voodoo so idk. the preformer manilfold would probaly be better than the RPM for me huh? its probaly a good idea to get the stroker crank balanced with the new pistons and stock rods too correct?  

I think that the performer RPM would still be better.

The crank has to be balanced with your components.  

new question. getting new heads for my 71 nova 355 with xr282h cam. found some RHS torker vortecs for $650 assembled, pair. anybody have any experiance with these heads?