K20 Suburban TBI Engine Build - The 1947 - Present Chevrolet & GMC Truck Message Board Network

*JCampbell* · 08-06-2011, 01:11 AM

'88 K20 Suburban. TBI 350. 4" lift on 35's. Dual purpose rig. We wheel it, but mostly "light", expedition-type wheeling (not a hardcore rockcrawler). We also use it for camping, and as such, I often pull a small utility-type trailer (5'x8', single axle) over the local fire roads to get to our favorite spots.

I could use some more low end torque and I was considering a few options. TBI will be the fuel delivery system on both options:

OPTION 1: Keep the 350, rebuild, cam, intake, headers.

Pros
Already have the engine
Parts are relatively inexpensive
Truck is already set up w/ this engine (simplified installation)

Cons
Small engine, big truck
Even after mods, it will still make less power that a BBC w/ the same mods

OPTION 2: Swap in a 454, rebuild, cam, intake, headers.

Pros
Big block power right out of the box
More power than a small block with what is comparatively the same cam, intake & exhaust

Cons
Parts cost a little more
Have to deal with getting it emissions legal (CA truck)
Need to source the engine and all TBI parts (nickle and dime effect)

Looking to get some opinions on what engine would be a better choice for a weekend wheeler/camping/expedition rig?

*Cam & intake would be from the Edelbrock Performer line of parts (or equivalent).

*JCampbell* · 08-06-2011, 11:37 PM

Bueler...Bueler...

cheepin · 08-06-2011, 11:38 PM

You didn't mention what gears you have.But my 3/ton suburban has 4:10s with stock tires and it pulls a 20ft tandem with my crawler on it 70mph no problem.I am thinking you need to regear lower to gain your power back and get the engine spinning in the power range.

*JCampbell* · 08-07-2011, 02:45 PM

Quote:

Originally Posted by cheepin

You didn't mention what gears you have.

Yeah, it's got (I think) 3:73s. I do plan on re-gearing the diffs when I tear the truck apart.

BLE 'BURBAN · 08-07-2011, 02:40 AM

build up your 350 to a 383 stroker.

67_SS396 · 08-07-2011, 04:44 AM

Build a stroker and use a more modern cam design. The Performer series cams are way outdated and leave a lot of useful power on the table.
Posted via Mobile Device

*JCampbell* · 08-07-2011, 02:47 PM

Quote:

Originally Posted by 67_SS396

Build a stroker and use a more modern cam design.

Not totally sold on the "Performer" cam. It was more of a reference to a mild, 50-state legal cam. Still have to pass emissions testing out here.

Mr. 250r · 08-07-2011, 06:03 PM

Just wondering do the mpg's matter or not but since your dealing with emissions i would just keep the 350

MTCK · 08-07-2011, 06:12 PM

One more vote for a stroker motor. I think there is still a guy who will burn you a custom chip for those TBI motors... Gears will help too. 4.10 or 4.56. Probably 4.10 since you don't have an OD.

08-06-2011, 01:11 AM	#1
JCampbell Account Suspended Join Date: Apr 2008 Location: Hesperia, Ca Posts: 1,332	K20 Suburban TBI Engine Build '88 K20 Suburban. TBI 350. 4" lift on 35's. Dual purpose rig. We wheel it, but mostly "light", expedition-type wheeling (not a hardcore rockcrawler). We also use it for camping, and as such, I often pull a small utility-type trailer (5'x8', single axle) over the local fire roads to get to our favorite spots. I could use some more low end torque and I was considering a few options. TBI will be the fuel delivery system on both options: OPTION 1: Keep the 350, rebuild, cam, intake, headers. Pros Already have the engine Parts are relatively inexpensive Truck is already set up w/ this engine (simplified installation) Cons Small engine, big truck Even after mods, it will still make less power that a BBC w/ the same mods OPTION 2: Swap in a 454, rebuild, cam, intake, headers. Pros Big block power right out of the box More power than a small block with what is comparatively the same cam, intake & exhaust Cons Parts cost a little more Have to deal with getting it emissions legal (CA truck) Need to source the engine and all TBI parts (nickle and dime effect) Looking to get some opinions on what engine would be a better choice for a weekend wheeler/camping/expedition rig? *Cam & intake would be from the Edelbrock Performer line of parts (or equivalent).

08-06-2011, 11:37 PM	#2
JCampbell Account Suspended Join Date: Apr 2008 Location: Hesperia, Ca Posts: 1,332	Re: K20 Suburban TBI Engine Build Bueler...Bueler...

08-06-2011, 11:38 PM	#3
cheepin Registered User Join Date: Nov 2009 Location: Parachute, CO Posts: 183	Re: K20 Suburban TBI Engine Build You didn't mention what gears you have.But my 3/ton suburban has 4:10s with stock tires and it pulls a 20ft tandem with my crawler on it 70mph no problem.I am thinking you need to regear lower to gain your power back and get the engine spinning in the power range. __________________ 1984 1ton 4x4 crew cab dually 6.2 diesel,465,205,D60,D70,1987 3/4ton 4x4 suburban 5.7 FI350,TH400,208,1985 CJ-7 FI406,465,205,D60,FF14, 1970 Jeepster 350,465,205,D44,FF14,

08-07-2011, 02:40 AM	#5
BLE 'BURBAN In the Forgotten far North. Join Date: Jul 2007 Location: Anchorage, Alaska Posts: 2,627	Re: K20 Suburban TBI Engine Build build up your 350 to a 383 stroker. __________________ 1987 R3500 CREW CAB DUALLY (BIG RED)Acquired 06/12/2015 1990 chevy suburban V2500 5.7L My cluster Mods-Nov 2007 overhead console Stereo install Round 2 Aug 2009 Heated/turn signal mirror upgrade

08-07-2011, 04:44 AM	#6
67_SS396 Registered User Join Date: Mar 2000 Location: Blue Ridge, Tx Posts: 1,172	Re: K20 Suburban TBI Engine Build Build a stroker and use a more modern cam design. The Performer series cams are way outdated and leave a lot of useful power on the table. Posted via Mobile Device __________________ Fawker Fab three seater rock crawler buggy 498 BBC/SM465/203/205 doubler, propane, 5.13's, 42" PB Rockers '66 C10 - The new hot rod '77 3+3 Dually - 12 valve 4wd conversion tow rig project '28 Ford 2 door sedan street rod RevLimit Offroad "Hang on beer, we can do this."

08-07-2011, 06:03 PM	#8
Mr. 250r Registered User Join Date: Dec 2010 Location: freeburg, illinois Posts: 885	Re: K20 Suburban TBI Engine Build Just wondering do the mpg's matter or not but since your dealing with emissions i would just keep the 350 __________________ 1987 Chevy V30 - http://67-72chevytrucks.com/vboard/s...d.php?t=573854 1988 IROC-Z Camaro - 305/T5 T-Top 1989 GMC V35 - Marbolo Express http://67-72chevytrucks.com/vboard/s...d.php?t=596850 1991 V2500 Suburban Silverado - Sold 1991 V2500 Suburban Scottsdale - Big Nasty http://67-72chevytrucks.com/vboard/s...d.php?t=497423 2001 Ram 3500 5.9 H.O NV56 EC DRW - Sold 2003 1500 Silverado 2004 Ram 3500 5.9 H.O NV56 CC DRW - Sold 2005 Silverado 2500HD 6.6/ZF6 CC LWB

08-07-2011, 06:12 PM	#9
MTCK Registered User Join Date: Dec 2009 Location: Fairbanks, AK Posts: 1,830	Re: K20 Suburban TBI Engine Build One more vote for a stroker motor. I think there is still a guy who will burn you a custom chip for those TBI motors... Gears will help too. 4.10 or 4.56. Probably 4.10 since you don't have an OD. __________________ -Marcus 1991 V3500 L29 454 4L80E NP205 D60/14 Bolt 4.56's 1984 K30 292 TH400 NP205 D60/14 Bolt 4.56's flat bed 7'6" Meyer Plow 2022 Silverado 3500 L8T Project Daily Driver Project Heavy Hauler Project Plow Truck



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