Replacing the TBI engine, suggested upgrades or changes?

[1STLS1]

I decided to install a TBI 5.7 LO5 Goodwrench crate motor I pulled from another vehicle in my '87 K10 with a tired 5.0 TBI. It ran and drove well so it should be just plug and play. My goals are reliability, drivability, fuel economy, and towing. I don't see a reason for it to ever be over 5k rpm and would need it to pass local emissions which is a dyno test and verify the evaporation system isn't leaking. An issue I currently have is I am running 33" tires vs the factory 31" with the factory 3:73 ratio and at 45 mph, it's in and out of lock up. It's annoying, I am hoping the additional torque will make it less of an issue as I am not going to swap gears.

The block has the ability to use a factory roller cam but currently has flat tappets in it. Is it worth it to put a mild roller cam in it? A more aggressive flat tappet cam? Adding an intake? TBI mods like salad bowls and injector spacers? Any other suggestions?

Thanks!

 

[Edelbrock]

Assuming the motor has some miles on it, I would focus on getting it tuned up as much as possible and leak-free before installing. Maybe a new fuel injector, premium plugs and wires, cap, rotor, etc. So before trying to go above what the original factory performance is, get it back to original performance as a starting point. If you lost 10% power due to old worn parts, then restoring that 10% with a tune up is far easier and cheaper than gaining 10% with a new style cam, and these expensive upgrades can never be truly utilized if the engine is not in tip top shape tune up wise. Maybe you already did that stuff, but if not, then these steps may help you or someone else reading this.

 

[1STLS1]

Assuming the motor has some miles on it, I would focus on getting it tuned up as much as possible and leak-free before installing. Maybe a new fuel injector, premium plugs and wires, cap, rotor, etc. So before trying to go above what the original factory performance is, get it back to original performance as a starting point. If you lost 10% power due to old worn parts, then restoring that 10% with a tune up is far easier and cheaper than gaining 10% with a new style cam, and these expensive upgrades can never be truly utilized if the engine is not in tip top shape tune up wise. Maybe you already did that stuff, but if not, then these steps may help you or someone else reading this.

I agree with you but the engine was in great shape to begin with, it only had 10K miles after it was installed before the truck body rusted away from the CA coast, dealer maintained with new distributor and rebuilt throttle body weeks before they gave up on it. I have new AC Delco tune up stuff along with alternator, starter, sensors, hoses, belts, etc. I am not afraid spending a couple bucks to do it right because I only want to do it once. When I finish, I only want to open the hood for oil changes for the next couple years

 

[gmbellew]

grab the PROM from the 5.7. you will need it. I also assume you are using the TBI from the 350 with the 350 injectors? I think 305 and 350 trucks used the same ECM, just different PROMs.

I'd keep the 350 stock cam. straying too far results in the need to get a custom tune.

 

[Slooptin]

If your block has the bosses for the roller lifter retainer spider in the valley, you can upgrade to a roller cam. I pulled almost everything I needed from a junkyard motor (cam retainer, spider, dog bones) and ordered new lifters, new double roller timing set, and a stock vortec 350 cam from rockauto. Only thing I had to really work to find was the melonized distributor gear (only because dizzy shafts vary in size so you have to measure what you've got). No tune and it ran great until I took it off the road for some repairs a few months ago. I'm ~$400 into it and I probably could have done it cheaper if I snagged everything but the dizzy gear and a new timing chain from the junkyard.

 

[Fat 454]

Have you contacted Brian at Harris tuning, WV? - Harristuning.com His site has a lot of great info regarding cams, chips and other ideas to get the best out of TBI.
Yes - he likes rollers..
I am picking up a 90 SWB with a 350 TBI set up this weekend. It has an NV3500 and I am looking to upgrade to a MkIV big block, but with edelbrock TBI intake and heads ... I have got a lot of ideas off his site, as TBI info seems hard to come by.

 

[Ricko1966]

Run it as is as @gmbellew said. Do the free tbi m9ds,salad bowl etc. Leave the cam alone the reward isn't worth the time trouble,hassles or expense. If your flat tappet hasn't gone flat yet,it's not going to or even if it does it's going to be a long time down the road. The cams are work hardened,your has hardened itself by now.

 

[1STLS1]

Have you contacted Brian at Harris tuning, WV? - Harristuning.com His site has a lot of great info regarding cams, chips and other ideas to get the best out of TBI.
Yes - he likes rollers..
I am picking up a 90 SWB with a 350 TBI set up this weekend. It has an NV3500 and I am looking to upgrade to a MkIV big block, but with edelbrock TBI intake and heads ... I have got a lot of ideas off his site, as TBI info seems hard to come by.

I have looked at his site numerous times and am reaching out to hear real world examples. I never played with SBCs other than a couple TPI F bodies in the 90's and I just drove them.
I put a budget of $1000 for mods, just want to get the best bang for my buck.

 

[RanchWelder]

We're covering the options you requested in the following thread:

Options for tuning of Gen1 TBI in 2023

Hi, I'm trying to find out what are the options for tuning of the 1990 TBI system these days. From what I've learned the ECU has a PROM memory, a one-time programmable chip that stores the base tune and adjustments are done on the go using inputs mostly from O2 sensors. That's similar to what...

www.gmsquarebody.com

Your money is best spent roller-izing what you have and burning a chip.

email me at my sig if you want any detailed info or ask in the other thread after re-reading the comments?

LS will be overkill unless you have money to burn.

Work with what you have and keep it simple.

 

[1STLS1]

We're covering the options you requested in the following thread:

Options for tuning of Gen1 TBI in 2023

Hi, I'm trying to find out what are the options for tuning of the 1990 TBI system these days. From what I've learned the ECU has a PROM memory, a one-time programmable chip that stores the base tune and adjustments are done on the go using inputs mostly from O2 sensors. That's similar to what...

www.gmsquarebody.com

Your money is best spent roller-izing what you have and burning a chip.

email me at my sig if you want any detailed info or ask in the other thread after re-reading the comments?

LS will be overkill unless you have money to burn.

Work with what you have and keep it simple.

Thank you for bringing this up, I have been reading that thread and still thinking about what to do. I agree on the roller cam set up but doing it with new parts gets expensive

I started the swap part today, getting the old motor out first, we will see.

 

[RanchWelder]

.

 

[RanchWelder]

That's my affordable formula.
New oil pump and cam bushings, forged DSS pistons, Summit racing rods, GM Performance crank and no change in bearing sizes.

(New bearings at the stock sizes that were in the clean crankshaft journals spec'd out OK).

We did use a $400 HQ billet aluminum cylinder hone and polish the cylinders using a bungie cord hanging system and a HD 1/2" drill for well over an hour.

Lots of reaming fluid. Be sure to clean up the passenger side where the piston slap is more prominent. My block had 92K. Removing the glaze is critical for ring break in.

The DSS Summit Racing pistons and rings are very nice. Excellent QC and shipping. The rods were branded Summit and match the Scat versions, EXCEPT... they came with better hardware and are rated better than the entry level Scat, for sale on Summit! Buy the Summit Racing Piston rods.

My mentor ran a HD Diesel Engine / transmission shop for decades.
He was skeptical of my choices until we verified all the sizing and the final assembly rotation. It came out very good.

We opted to NOT go a half size larger on the Crank main at the rear seal. He insisted there was no reason for Chevy to fight tolerances to such a tight degree. When I followed his advice, the crank rotates perfect.

Many people insist on machining everything. What learned was how to make a good decision and save a buck without lowering quality control.

The rods came sized for stock bearings and everything worked out great in a 99' roller Gen1 block, so far.

ARP man studs to replace the OEM stretch bolts. No way would ai risk all these new parts and re-use the main cap stretch bolts.

I'm almost at start up, next week.

My plan is to get 50k out of the OEM rollers, after a thorough cleaning and replacing any that did not meet the standard with a backup set of used roller donors.

When replace them at 50k, Lord willing, will spend the money for the High Treated OEM Chevrolet Performance Cadillac Rollers, which are heat treated more than the OEM truck engine rollers

Very few non-needle bearing after market roller lifters, in the affordable range, are heat treated. Chevrolet Performance only.

Search my posts for cleaning OEM roller lifters?

TBI Chips and SPR TBI boring is my formula. Brian is very good to deal with. Don't waste his time asking the same questions we already covered here, OK?

He know's we are discussing his work here.

Make up your mind and focus on the small details is my advice.
The small stuff will push your wallet faster than most people think.

By containing the expenses with a proven system, like TBI Chips formula, you end up with much lower build cost and a higher ratio of $$$ vs real world useful performance.

Don't over think it.
It's gets over complicated and needlessly expensive with a stubborn head.