383 stroker tbi to carb swap

[papabear383]

Hey guys I'm new here so first off id like to say hello! I have a 1995 gmc yukon that has a loooong list of mods done to it and im looking to make that list even longer! The truck has a 6" pro comp lift on it with 35's. I have 4.56 gears front and rear with the sf 14 bolt rear axle with a detroit tru trac. I swapped an nv4500 5 speed manual in it, and it also has a mild 383 stroker in it. I am currently still using the tbi fuel injection, but i want to make more power and i have a custom chip, and all the other goodies that are supposed to make the tbi run smoothly, but it still doesnt run the way I want it to.I want to put a carb on it so i can make some real power and make it run like a real 383, and not have to deal with the worry of a custom chip, and the computer issues. With that being said, im looking for a little guidance on what to run. The truck is used specifically at the silver lake sand dunes for playing, and going out for a cruise on a summer night. The 383 thats in it now is a crate motor from Tuff Dawg Engines and I will post the specs of that. I know I want to change the heads, put a bigger cam, but I have no idea on what to run. Im not sure what size the carb should be, so please bear with me during this process, as I have no experience with carburetors, or going internal on this engine.

383 stroker tbi from tuff dawg engines
--The cam has a advertised duration of 270 Int. and 280 ex. Duration @ .050" is 204 Int. and 214 ex. Ground on a 112 Lobe center.
-Stock TBI heads
-9.2 to 1 hypereutectic pistons
-3.750" stroke cast/steel crank
-5.7" forged rods

As you can see it is a very mildly built 383, so if someone could point me in the right direction so i can get the ball rolling! Thanks

 

[retorq]

If you want "real" power ditch those ****** stock heads. With a properly sized TBI system you won't make much more power then you will with a carb. Some stock Vortecs you will pick up a bunch of HP. When I did the top end swap on mine it was like a new truck and that was with the stock TBI cam.

Who did your custom chip??

 

[Gzes]

Yea vortec heads are the way to go. Its on my list but for carb a good eddlebrock 4 barrel will be good but you need a manifold, carb, dizzy, fuel pump

 

[papabear383]

Vortec heads were a part of the plan, and Brian at tbi chips.com burned my chip. I have a bigger throttle body on the truck, and every time I modify the truck I always have to worry about how the computer is going to react, and I really don't like having to have a new chip burned and I especially don't like how I have to do business over the Internet, if there was a local tbi performance shop around I'd stick with the tbi, but there isn't.

 

[retorq]

You can get setups that allow you to use an EEPROM chip and tune as you go like the LS1 guys do.

 

[papabear383]

i have no interest in sticking with the tbi setup anymore. Ever since i started to modify the engine its been nothing but an absolute head ache. the truck runs OK, sometimes and other times it runs like garbage.

 

[retorq]

You probably have a loose wire somewhere, my temp sensor wiring pulled out and it did that, would kick out of OD running down the highway, started dumping extra fuel cause it thought it was cold, etc. If you don't like it get rid of it, it's not my truck so I don't give a **** lol.

You'll need a 750 or so to get the most power, smaller carb would give ya more low end torque. I like the older barry grant claw stuff personally ... I think you will need an intake/head swap atleast since these TBI intakes had a "Special" bolt pattern and I doubt there are carb intakes built for these heads.

That cam is on the small side for a 383 too, you don't mention if it's roller or not, I'm guessing not by those numbers. I would swap that too ... you'll need to address the coolant crossover with a Vortec head swap into a 95 too. That heater valve has to go or you can drill the coolant passage hole yourself and use the passage built into the block and water pump.

You'll need to address the distributor too obviously ...

 

[papabear383]

yes the cam is a flat tappet, and any recommendation on how much bigger i should go? the truck is strictly for climbing sand dunes , also what about push rods, and rocker arms , valve springs, etc.? I know what kind of intake manifold i need , and the distributor should be an HEI im pretty sure

 

[retorq]

Sand dunes huh ... you need lots of RPM for that (guessing) so I would go with some beehive springs and retainers (std retainers here are fine, you won't need the light weight stuff since stock is lighter then a normal one anyways), some Comp Magnum pushrods (stronger then stock and worth the piece of mind they will give ya), 1.52 Pro Magnum rockers (chro-mo roller based ), Edlebrock RPM Performer (may have an issue with clearance under a stock hood), Cam ... hyd roller is fine, something alone a 240/250 @ .050. All that with some Vortec heads will get it moving, might even be worth it to get some better heads, RHS or something that will flow more.

You don't say what size your truck is, 4 door is gonna need more low end then a 2door to get moving so a smaller cam/carb would feel better.

You don't mention your exhaust either, stock those non-vortec Y pipes were horrible ...