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89 C10 engine swap, keep the TBI or go to a CARB?

  
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89 C10 engine swap, keep the TBI or go to a CARB?

 
Shawn S Shawn S
New User | Posts: 3 | Joined: 01/14
Posted: 01/12/14
07:19 PM

My son has a 1989 C10 and we are building a 1994 350 motor for it. The motor came out of a van. We are wanting to put a set of heads on it with a new intake and cam too. My question is should we keep the TBI that's on the truck or swap to a CARB? What is the biggest cam we can put in there if we do keep the TBI? Any other issues we should be concerned about?  

ddemello ddemello
New User | Posts: 3 | Joined: 01/14
Posted: 01/12/14
07:44 PM

i read something about cfm technologies. they have tbi upgrades. maybe you might want to go to their web site and look into what they can do for you?  

tuffnuff tuffnuff
Moderator | Posts: 7828 | Joined: 12/09
Posted: 01/12/14
09:24 PM

Icon QuoteShawn S:
My son has a 1989 C10 and we are building a 1994 350 motor for it. The motor came out of a van. We are wanting to put a set of heads on it with a new intake and cam too. My question is should we keep the TBI that's on the truck or swap to a CARB? What is the biggest cam we can put in there if we do keep the TBI? Any other issues we should be concerned about?

Start your cam search with the link below.

http://www.compperformancegroupstores.com/store/merchant.mvc?Screen=PROD&Store_Code=CC&Product_Code=12-404-4&Category_Code=HFTCC

Smile  
When The Flag Drops.,.

tuffnuff

The Bull ***t Stops.,.
tuffnuff

P. Engineer, Engine Builder

wayne712222 wayne712222
User | Posts: 208 | Joined: 10/13
Posted: 01/13/14
12:10 AM

you can go to Vortec heads if you want to invest in the GMPP vortec head TBI intake..

that makes it a bolt in.. everything will fit and the vortec heads flow so much better...

only thing.. you might want to carefully check the part numbers on your injectors and compare them to the flow charts online..  there are some 9C1 police car 5.7 injectors that flow slightly more.. or complete holley throttle bodies..


engine... tbi bore...pin colors. flow.    
2.8L~~ | 1-3/8 ~~|Blk/Wht |33 lb/hr |GM5235430*RPD
_________________________________________________
4.3L~~ | 1-11/16 |Yel/Blu |45 lb/hr |GM5235203*RPD
_________________________________________________
5.0L~~ | 1-11/16 |Grn/Wht |40 lb/hr |GM5235279*RPD
_________________________________________________
Pickup
5.7L~~ | 1-11/16 |Orn/Blk |55 lb/hr |GM5235206*RPD
_________________________________________________
Cop car
5.7L ~~|1-11/16 ~|Yel/Brn |65 lb/hr |17084327-ACR
_________________________________________________
Late big block pickup
7.4L ~~| 2" ~~~~~|Blu/Blk |80 lb/hr |GM1708430*RPD
_________________________________________________
big block pickup
7.4L ~~|2"|Drk Red/Drk Blu|90 lb/hr|GM5235231*RPD  




one last thing.. if you are going to run the GM factory throttle body.. engine off.. open the throttle part way.. wiggle the throttle lever.. does the shaft wiggle in the bore..  there have been a LOT of wear issues that cause rich idle and stalling issues..  loose would be like this (O ) ( O)  where tight would be like this(O)

there are shops that can rebush the throttle shaft bore..

if the engine has the small cap HEI.. please check the reluctor for signs of cracking of the second layer..  this causes rough running..  

Shawn S Shawn S
New User | Posts: 3 | Joined: 01/14
Posted: 01/15/14
05:16 PM

Thanks for all the replys.  Do the heads have a part number ? Do certain ones work better than others?
I found a comp cam that will work with that motor. It's the 268ah cam. I thought about going with a aftermarket TBI from holley.
Should we upgrade the ignition system? We're going to put headers on it too.  

tuffnuff tuffnuff
Moderator | Posts: 7828 | Joined: 12/09
Posted: 01/15/14
07:24 PM

The 906 and 062 heads are identical except for the bumps on the ends.
10239906 casting has one large single hump.
12558062 casting has 3 small humps.
If either of these two castings have not been altered by GM and the part number changed from 12558060 or altered by someone else (previous owner, etc.), the heads produced by either casting will be identical except for the external cosmetic difference. Both castings are used to make the 12558060 Vortec heads which are the true unaltered Vortec heads.
Heads from both castings come out of their cast IDENTICAL except for the minor cosmetic external differences.
Both heads have 1.94" intake and 1.5" exhaust valves.,. in stock trim these heads will only support .460" lift, leaving .030" to .040" clearance before retainer/stem seal interference occurs.
Machining the guides allows for .500" to .550" lobe lift and sufficient clearance.

Bumps

Vortecheadendview

Old 461 Chamber on left and Vortec on right

461Andvortec

Smile  
When The Flag Drops.,.

tuffnuff

The Bull ***t Stops.,.
tuffnuff

P. Engineer, Engine Builder

shyrgfuh3 shyrgfuh3
User | Posts: 50 | Joined: 01/14
Posted: 01/15/14
08:43 PM

hello

what do you want:

mild, moderate or rough idle?

vacuum FOR POWER BRAKES?

FWY FLIER, LITE TO LIT DRAG CAR OR INBETWEEN?

tire roaster or tire warmer?

one of the most important things is to maintain good compression levels.

use the free online calculator at k b pistons to determine your compression.

you basically want to be around 9.75 to 1 with iron heads and 10.5 to 1 with aluminum.

that 268 has a mild lope and good lower mid range.

it likes around 350 gears and a 2200 stall.