Is 300 hp possible from a tbi

[1997]

Just to add to the discussion. I purchased an early 88 K2500 7200gvw from the original owner today. 49,000 original miles. It has a 350, 700R4 and 14 bolt with 4.10 gears.

nice score, how about posting pic in the eye candy thread:
https://www.gmt400.com/threads/show-n-tell-lets-see-some-eye-candy.47889/

4:10's is a nice option for a 7200 gvw 2500.

 

[mariodave]

I converted a 1989 instrument cluster to a 1992-1993 cluster with a tach. I had to splice the later style plug to the 89 dash harness. I had to move 2 wires, but the circuits are the same except for the VBSS. The original cluster contains all those circuits. The later cluster requires an external speedometer module and the circuits must be moved from the cluster to the VBSS. The good news is that the modules are what corrects the speedo for different gear ratios, not the whole cluster like 88-90. All these parts are cheap at the salvage yards.

 

[evilunclegrimace]

I converted a 1989 instrument cluster to a 1992-1993 cluster with a tach. I had to splice the later style plug to the 89 dash harness. I had to move 2 wires, but the circuits are the same except for the VBSS. The original cluster contains all those circuits. The later cluster requires an external speedometer module and the circuits must be moved from the cluster to the VBSS. The good news is that the modules are what corrects the speedo for different gear ratios, not the whole cluster like 88-90. All these parts are cheap at the salvage yards.

You do not have to replace the '88-'91 clusters you can "reprogram" them with a GM tool and new chip.

 

[HotWheelsBurban]

My 88 k1500 also came 5.0 th400 9.5 14bolt.

I used to have a 90 GMC R2500 suburban with the tbi 350 and a th400 trans. That truck would pull a house but just not real fast on the highway. (4.10 rear end gearing)

 

[HotWheelsBurban]

I used to have a 90 GMC R2500 suburban with the tbi 350 and a th400 trans. That truck would pull a house but just not real fast on the highway. (4.10 rear end gearing)

And it was 8600 gvw too, with the skinny 10 ply 16" tires, not having overdrive with that gear set wasn't fun on the road. Once dad and I rebuilt the front end over a couple years it handled fairly well for a big tall box. I miss that truck....was a little easier to fix than my 99, and l don't want anything newer than my vortec suburban.

 

[Txlock]

My goals were similar, needed a fresh motor and wanted simplicity and driveability. Took a tbi block with roller provisions, comp roller cam, vortec stock style roller lifters and retainer. Stock type dished pistons. EQ iron hybrid heads.(vortec 64cc chamber with tbi intake manifold pattern) stock intake manifold, tbi with some of the “ultimate mods” and stock ecm/chip. Purrs like a kitten, pulls like a mule.

made 311hp/385ftlbs on the dyno.

So yes you can achieve what you are asking.

I just found this post and was curious did you have to do anything to your computer? And if not can you give me the details your build? I have a 92K 1500 and I have the motor out of a 95K 1500 sitting on a stand. I want to do exactly what you described. I have a couple extra 350 throttle bodies and I plan on doing the ultimate Tbi mods I also ordered the AC Delco police package injectors for these year model trucks. I have long tube headers I have an Edelbrock performer TBI intake. I currently have a summit racing 1102 cam but I’m not loyal to that. But if you don’t mind I would love to know exactly what you did to achieve that because I would love to re-create it.

 

[Gramps]

Computer is stock, although I’m sure would benefit from further fine tuning. The goal was reliability and driveability. The bonus was the 100 hp gain.
I started with a shortblock from TriStar engines out of Wisconsin, pm me I’ll give you my contacts info there) it was a 4 bolt tbi block with roller provisions, .040 over. They installed the comp cams cam(I don’t have the number handy but it was one of their efi roller grinds). I added a set of engine quest tbi/vortec hybrid heads. (Get them bare and put your own parts in them) I had The seats ground down fir a little extra clearance. Stock intake on top, 454 injectors 14 psi, 17* initial timing.

 

[L31MaxExpress]

Computer is stock, although I’m sure would benefit from further fine tuning. The goal was reliability and driveability. The bonus was the 100 hp gain.
I started with a shortblock from TriStar engines out of Wisconsin, pm me I’ll give you my contacts info there) it was a 4 bolt tbi block with roller provisions, .040 over. They installed the comp cams cam(I don’t have the number handy but it was one of their efi roller grinds). I added a set of engine quest tbi/vortec hybrid heads. (Get them bare and put your own parts in them) I had The seats ground down fir a little extra clearance. Stock intake on top, 454 injectors 14 psi, 17* initial timing.

Was that a typo or did you really mean 17*. Stock spec is 0* or TDC. The WOT advance from the computer can be as much as 24-26°. Cruise timing can be over 40°. At 17° you have as much as 43° total at WOT and cruise timing nearly 60°. I could see 8-10* with your culinder head and cam change but 17* seems like a lot.

 

[Gramps]

Was that a typo or did you really mean 17*. Stock spec is 0* or TDC. The WOT advance from the computer can be as much as 24-26°. Cruise timing can be over 40°. At 17° you have as much as 43° total at WOT and cruise timing nearly 60°. I could see 8-10* with your culinder head and cam change but 17* seems like a lot.

not a typo. 17* initial is what it’s set at.