Question on 1990 5.0 IROC TPI swap

[ck80]

With all due respect, where are these 20+ year old, less than 100k mile truck engines, for cheap?

In wrecked vans and pickup trucks, Tahoe 4dr and suburban around metro Atlanta. To a lesser extent more rural Georgia.

I'm not talking 20k mile motors. I'm talking 85k, 95k motors.

Trucks are going into salvage auctions as well to buy the whole thing.

I had a 1994 that nobody would buy the whole thing with a 4l80e HD that ran and drove, 4.10 gear 14 bolt sf single rear wheel axle and good transforce tires too. Id offered it varied prices for the whole truck, cat converter included but salvage title between $1250-1500 with no takers because there were cheaper options. I tried off and on over a year.

We rented a 12x40 work bay with 18 foot ceilings to chop it and a couple other stragglers up and simplify things finally. Going to keep it for myself now.

All the fanboys want ls engines to follow the lemmings. SBC prices are WAAAAY down.

 

[Texas82GP]

In wrecked vans and pickup trucks, Tahoe 4dr and suburban around metro Atlanta. To a lesser extent more rural Georgia.

I'm not talking 20k mile motors. I'm talking 85k, 95k motors.

Trucks are going into salvage auctions as well to buy the whole thing.

I had a 1994 that nobody would buy the whole thing with a 4l80e HD that ran and drove, 4.10 gear 14 bolt sf single rear wheel axle and good transforce tires too. Id offered it varied prices for the whole truck, cat converter included but salvage title between $1250-1500 with no takers because there were cheaper options. I tried off and on over a year.

We rented a 12x40 work bay with 18 foot ceilings to chop it and a couple other stragglers up and simplify things finally. Going to keep it for myself now.

All the fanboys want ls engines to follow the lemmings. SBC prices are WAAAAY down.

Fair enough. I'm just surprised there are trucks that old, that low milage that are junk. My 2008 has 189k miles on it.

 

[ck80]

Fair enough. I'm just surprised there are trucks that old, that low milage that are junk. My 2008 has 189k miles on it.

Has to do with the massive volume of vehicles, how many drive short distance in the metro area. And in some cases, they sell them for parts because they fail emissions and are so old. Also bunches of county and government vehicles

I bought my 77 c10 with around 75 or 80k original on it, i forget what... it had never left the county till I bought it. Rough shape, but original and not rusted. About 7 years later or so it's up to the 90k mark,.100k rollover, here we come! Going to need to have it back to nearer showroom condition for that event...

 

[Texas82GP]

It's different there than it is here. The square bodies and GMT400's are gone here. Nothing rough here has less than 100k miles on it. Nothing that low mileage (trucks) gets parted out. It gets fixed and pressed back into service. I'm jealous of the opportunities you have.

 

[DRIVEN]

I got a line on a '90 5.0 TPI from an IROC. Comes with the 700R4 trans. Looks likes its mostly all there from the photos. It has the wiring harness but I can see there is an empty brake on the both sides. Probably a pump of some kind. Claims to have 48K miles on it. For my plans on my Elco this might be just the ticket. But I'm curious of what to look out for and gotchas on a swap for this.

Disregarding the trans for the moment because I know I'll need a new cross member and driveshaft etc...

• What do I need to look out for in the motor?
• Are there parts that are really expensive or hard to find that I should make sure are included? Like the CPU?
• Will this unit otherwise drop it?
• How about the wiring?

If this isn't too complex I'll pursue it. I remember these motors made really good low end torque and decent power. More than enough for a street car daily driver.

I appreciate the comments in advance, thank you.

It's basically just a SBC swap. Aftermarket harness and some fuel system work would make it a slam dunk. Not sure where you got the 275hp number but 305 TPI was nowhere near that. I remember reading in a magazine somewhere that, "The TPI were the best truck engines GM ever made." and I 100% agree. They made incredible torque up to 4500rpm and then fell flat on their faces. Not necessarily a bad thing at all, as long as that's what you want.

 

[ck80]

It's different there than it is here. The square bodies and GMT400's are gone here. Nothing rough here has less than 100k miles on it. Nothing that low mileage (trucks) gets parted out. It gets fixed and pressed back into service. I'm jealous of the opportunities you have.

I think it's nearing that tipping point. People are seeing the absurd prices both new trucks and older restored trucks are pulling. Deals are still out there but you see lots of flippers buying things and either bumping the price way up, or, taking them a few hours away to flip.

Just 5 years ago I bought a front clip wrecked 80k mile 2dr regal with mint interior and.no rust or body defects aside from the accident for around 400 give or take plus a tow home. Haven't seen a deal of that caliber in a while now. I'd guess we're about 5 years from what you describe.

 

[Clone TIE Pilot]

It's basically just a SBC swap. Aftermarket harness and some fuel system work would make it a slam dunk. Not sure where you got the 275hp number but 305 TPI was nowhere near that. I remember reading in a magazine somewhere that, "The TPI were the best truck engines GM ever made." and I 100% agree. They made incredible torque up to 4500rpm and then fell flat on their faces. Not necessarily a bad thing at all, as long as that's what you want.

305 TPIs were rated 190 WHP with a auto trans, 215 WHP with a manual. TPI doesn't choke a 305 as much as a 350 at high RPM. TPI was originally designed for 305s as GM was unsure if 350s had a future back then.

Personally I rather go with a Vortec 350 and reuse the CCC on it. To go that route you would need to either run a external exhaust supply line to the EGR or run a ZZ4 chip that deletes EGR. GM does sell a Vortec intake manifold with a Qjet spreadbore pattern and EGR provision, #12496820.

 

[jiho]

Search L31 or LO5 350 v8 truck builds.

They have roller lifters so no zddp or wiped cam worries, but can run off the original technology in your car.

You don't need to mess around with wiring conversions - they don't need a computer, but, if you REALLY wanted to you could use the stock one and setup.

No need to worry about out of production MAF and other sensors that drive you into cheapo Chinese or junk remanufactured as they fail.

Because they aren't fuel injected, you don't need a new gas tank, new sending unit, new larger diameter fuel lines, or to buy and wire in an electronic fuel pump.

A used motor will only cost you around 300-500 bucks complete top to bottom front to back with around 100k or less on it, leave lots of money to buy cam, heads, intake, and carb to really wake it up to the around 400hp range.

Stock from the truck (or B-body) the LO5 has the other "GM Halfway House" fuel injection -- TBI. Which needs a computer. No MAF though.

 

[motorheadmike]

There are a pair of Vortec 350s ('96 and '99) about an hour and a half West of here for $500 each. I am really considering grabbing one for Natasha's Camaro. The '99 should be a full roller engine with the 906 heads.

I still have a Holley Vortec EFI single-plane intake, Edelbrock elbow and LS 78mm TB I could use to put some pep in it's step. The factory TPI injectors should support fueling just fine, and work on the stock confuser (the SD VE table is just a suggestion, right)... and it would actually rev.

Hmmm...

 

[ck80]

Stock from the truck (or B-body) the LO5 has the other "GM Halfway House" fuel injection -- TBI. Which needs a computer. No MAF though.

Correct. Which is a low buck cost intake and carb swap away from disappearing but retaining all the other benefits while increasing hp and torque ratings