TBI or carb for performance

[80 Chevy K20 4x4]

I just got a 84 Silverado K5 4x4 Blazer with a 6" lift, like new 35" Pro Comp XTerrain tires on 3/4 ton axles, TBI 350 motor, Turbo 350, and a NP 203 transfer case.

The problem is the motor doesn't produce as much hp and torque like my previous Chevys - 87 K20 4x4 with a TBI 350 and 700r4, or my 89 K5 4x4 Blazer with a TBI 350 and 700r4. It has the TBI factory wiring transplanted into the 84 with the VSS and Park/Neutral switch installed as well.

I'm trading my 92 Pontiac Trans Am Firebird for a 86 Silverado K5 4x4 Blazer this coming weekend that has a 6" spring lift, 37" Wrangler AT military tires, 3/4 ton axles with lockers , 91 TBI motor that has an Edelbrock cam, intake, and carb, 700r4 trans, NP 208 trans case.

I'm debating on which Blazer to make my wheeling rig, the 84 or the 86 K5? The body of the 84 is a little bit better then the 86.

To me it always seemed like a carbed motor produced better hp and torque vs the TBI motors I had, but the TBI motor has the better drivability aspect for off road wheeling.

What are your opinions on which Blazer would you make your wheelin' rig?

Thanks.

 

[79rustyk10]

The TBI one would be better off road.

Make sure you have acceptable gearing for the 35's. That makes a huge difference

 

[80 Chevy K20 4x4]

I have 4.10s in the 84 with the 3/4 ton axles, and the 86 has 3/4 ton axles with possibly 3.73s with lockers.

 

[ryoken]

I just got a 84 Silverado K5 4x4 Blazer with a 6" lift, like new 35" Pro Comp XTerrain tires on 3/4 ton axles, TBI 350 motor, Turbo 350, and a NP 203 transfer case.

The problem is the motor doesn't produce as much hp and torque like my previous Chevys - 87 K20 4x4 with a TBI 350 and 700r4, or my 89 K5 4x4 Blazer with a TBI 350 and 700r4. It has the TBI factory wiring transplanted into the 84 with the VSS and Park/Neutral switch installed as well.

I'm trading my 92 Pontiac Trans Am Firebird for a 86 Silverado K5 4x4 Blazer this coming weekend that has a 6" spring lift, 37" Wrangler AT military tires, 3/4 ton axles with lockers , 91 TBI motor that has an Edelbrock cam, intake, and carb, 700r4 trans, NP 208 trans case.

I'm debating on which Blazer to make my wheeling rig, the 84 or the 86 K5? The body of the 84 is a little bit better then the 86.

To me it always seemed like a carbed motor produced better hp and torque vs the TBI motors I had, but the TBI motor has the better drivability aspect for off road wheeling.

What are your opinions on which Blazer would you make your wheelin' rig?

Thanks.

it's because the TBI's have pretty anemic cams... the motor can be woken up a bit with bolt-on's, comp-friendly cam, chip, headers, etc..

I'll take EFI over a carb anyday, unless it's a high horse app...

 

[6.2Blazer]

The difference in power has more to do with how the other parts of the engines were different versus just carb vs. TBI. When the TBI engines came out in the late-80's they were a substantial improvement in power versus the previous generation carb'd versions (assuming comparing stock engines).

The other thing to keep in mind is that a TH350/203 (especially if still full-time) provide more resistance and have less gearing than a TH700/208 combo. TH350 only has a 2.5:1 first while the 700R4 is 3.06:1...same difference as driving two trucks but one has lower axle gears and thus will feel stronger off the line.