1990 Caprice Classic 305 to 350 crate swap, where and what?

MilitantPotato · #1 09-06-2007, 02:04 PM

She's getting on in years and I just got a nice bonus, so I figured I'd do an engine swap. She has a 305 TBI with a 200-4R tranny. It has 119,492 miles.

Where should I get a new crate engine, and what would be the recommended parts to replace that don't come with the crate while it's at the shop? Fuel pump, radiator, ECM, ???

I have about $4000 to spend on the engine, less would make the wife happier.

Any other bits of wisdom/advice are greatly appriceated.

Edited: Split into two threads.

MilitantPotato · #2 09-07-2007, 05:18 PM

I'm drawing blanks on this engine search, the 350/290 by GMPP seems in my price range after labor.
IF the local GM shop can swap the intake manifold, TBI and other expensive parts from my 305 so I can slowly replace them with after market.

Would the 350ci 290HP GMPP swap out with my 305 TBI without much hassle?

Just about every site listing it says pre 1979 due to emmissions, is this little beast able to be made street legal?

Link to the engine HERE.

DANZIGS · #3 09-08-2007, 01:07 PM

The cylinder heads would not allow your TBI manifold to bolt up. I know the center bolt heads you have on the 305 have different mount points. The TBI may not flow enough fuel to feed it at higher rpms either. I would just go with a reman 350 from your year. I can't think of the vin code off hand. All your parts will fit for a less stressful and cheaper install. You will be happy with the new found power and torque. The 200 4R tranny will live up better too, than with the 350 you showed. Just add a shift kit to make it more crisper and less band slippage. If you don't beat on it too much it will hold. You might need an adjustable fuel pressure regulator for the TBI to keep up at higher rpms. That should be it.

silicon212 · #4 09-08-2007, 02:32 PM

The engine you see has a 2-pc rear seal (won't work with your existing flexplate - big deal - they're about $30 anyways), and won't work with your existing intake manifold. On the 1987-up 'centerbolt' non-Vortec heads, the middle set of intake bolts (two on each side) are re-angled to 72 degrees, vs. the 90 degree angle of earlier designs (which the Goodwrench engine is one). This re-angling of the middle bolts makes it much easier to properly torque those bolts (as you can actually get a wrench on them), however it makes earlier 90-degree intakes obsolete. The reverse also applies.

I don't know what DANZIGS is saying by stating the TH2004R will live better behind the stock replacement than the crate engine, either. They're both 350s and they both put out about equal power (the 290 rating is gross BHP).

Also, in response to his remark about injectors - a reprogramming of the ECM will resolve that. You'd need to do that, anyway.

In my view, the only things really stopping you are the intake bolt angles - unless you can find an aftermarket GM TBI intake which has EGR, for the earlier engines.

emarkay · #5 09-08-2007, 09:31 PM

Man, I'd do an LS1-7 swap. Someone (I am sure) has done this, and how's 30 MPG AND 350HP sound...

Comments???

silicon212 · #6 09-08-2007, 10:11 PM

Quote:

Originally Posted by emarkay

Man, I'd do an LS1-7 swap. Someone (I am sure) has done this, and how's 30 MPG AND 350HP sound...

Comments???

Way too much work, unless you're dead serious. You will require an upgraded fuel delivery system to supply the fuel, an electronic-shift transmission, and the complete PCM and related wiring - this doesn't even include the minimum $3000 cost of the engine without these things.

If you want to go new-block, you can get a 5.3 Vortec engine for not too much (although you will still have to do the other upgrades) - we purchased a nice one complete for $350 on Ebay not too long ago. It was complete with intake, TB, injectors, coils, everything. That would be the way to go and the 5.3 is no slouch - especially in a 3600-lb Caprice.

DANZIGS · #7 09-09-2007, 09:26 AM

Well in my defense, the stock 350ci from that year was 195 hp and the 305ci was rated at 170hp. I took it as he was looking to freshen his ride up for a low cost to keep the wife happy. Believe me I'm there too. With only a 25hp difference I figured the 200 4R would be fine. If you got to replace the tranny anyways which you just mentioned then you might as well go to the 700R4. Stronger and a better first gear ratio. All the parts you need for the swap can be found practically at any junk yard, and cheaply.

silicon212 · #8 09-09-2007, 12:47 PM

Quote:

Originally Posted by DANZIGS

Well in my defense, the stock 350ci from that year was 195 hp and the 305ci was rated at 170hp. I took it as he was looking to freshen his ride up for a low cost to keep the wife happy. Believe me I'm there too. With only a 25hp difference I figured the 200 4R would be fine. If you got to replace the tranny anyways which you just mentioned then you might as well go to the 700R4. Stronger and a better first gear ratio. All the parts you need for the swap can be found practically at any junk yard, and cheaply.

Yes, there was a 25HP difference, but also a 40 lb-ft difference and therein lies the rub.

The 290hp crate motor puts out close to 200hp at the crank with all accessories running (SAE net HP).

MilitantPotato · #9 09-09-2007, 01:20 PM

A LS1-7 swap is a little out of my budget.

After a few (5) hours on google I found no IM's that fit a pre 1986, 350 non vortec, that supported TBI and EGR.

I don't mind spending a little extra for an intake, but it seems I'd have to go carburated, and I'm not sure how well that would work in my car, or what the cost would be for the conversion.

At this point, I guess my options are pulling one from a scrap yard (not what I'd want to do,) or getting a remanufactured engine from GM, would that be right? Is the 350/290 not even worth the extra hassle and expence over a stock 350? From my understanding on what you wrote Sillicon the difference won't be much.

A brand new engine isn't needed, just a dependable one, with a decent warrenty, and some grunt.

silicon212 · #10 09-09-2007, 01:44 PM

A factory reman for your model year would seem to make the most sense. A new one would have about a $400-500 premium over the 290 crate motor.

Actually - at Summit, there's a factory 350 crate motor (new) that would be a direct bolt-in for your car. It's advertised as a "truck/van VIN K" motor, the difference is it has a flat tappet cam vs. the hydraulic roller cam. It's $199 less than the 290HP crate motor.

http://store.summitracing.com/partde...8&autoview=sku

Edited to add (because I forgot to above) the TH2004R should live for a while behind the 350, as long as you don't find the newfound extra power intoxicating and proceed to do burnouts.

I know - that's exactly what happened to the 2004R that *used* to be in my car.

MilitantPotato · #11 09-09-2007, 06:28 PM

It says it's for EFI, is that an issue?

My 2004r is on the way out, that TCC solenoid issue I had a few months back caused some damage.
Found a small quarter sized thin washer piece in the pan along with some shavings.
I'm looking at a bowtie level 2, or pro-built road race, but havn't settled yet.

silicon212 · #12 09-09-2007, 07:04 PM

Quote:

Originally Posted by MilitantPotato

It says it's for EFI, is that an issue?

My 2004r is on the way out, that TCC solenoid issue I had a few months back caused some damage.
Found a small quarter sized thin washer piece in the pan along with some shavings.
I'm looking at a bowtie level 2, or pro-built road race, but havn't settled yet.

Your car has EFI so there's no issue.

I'd get the 700R4 - Bowtie Overdrives has a nice site with a lot of good info on it. If their product is as good as the info on their site, I'd recommend them in a heartbeat. Remember though, a 700R4 will require a 1" shorter driveshaft (as the 700R4 is ~1" longer than the 2004R), and most likely a 700R4 crossmember, unless your new transmission has a mount pad on the tailshaft extension housing - in which case a 2004R crossmember will work.

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