Engine Swap?

Discuss anything related to drivetrain mods here (Engine &Transmission Swaps, lift, gearing, exhaust, etc)

Moderator: Staff

Engine Swap?

Postby cc9696 » Tue Apr 20, 2021 8:47 pm

I have a 1989 Trooper LS 2.8, 5spd with a cooked engine. I was informed that a 3.4 is a perfect swap. I have a 2004 Chevy Impala FWD with a 3.4, can I use this engine? Thank you
Drives on Pavement
Posts: 1
Joined: Tue Apr 20, 2021 8:37 pm
Has thanked: 0 time
Have thanks: 0 time


Re: Engine Swap?

Postby Ed Mc. » Tue Apr 20, 2021 10:38 pm

cc9696 wrote:I have a 1989 Trooper LS 2.8, 5spd with a cooked engine. I was informed that a 3.4 is a perfect swap. I have a 2004 Chevy Impala FWD with a 3.4, can I use this engine? Thank you

Howdy, the short answer is "It's not a simple bolt-in", however the '04 3.4 will bolt up to the ZuZu MUA5 transmission, as the ZuZu is using the standard GM FWD 60-degree-V6 bell housing bolt pattern.

Does the Impala 3.4 have a cast-aluminum oil pan? If so, you'd have to deal with that. IDK if a stamped-steel 4WD Deep-Sump oil pan can be adapted to the later-style block. The aluminum oil pan will interfere with the front cross-member in the Trooper. I've seen some swappers cut sections out of the pan and weld it up to eliminate the interference, so that's something to look into.

You'd also have to deal with the EFI and related systems, joining them to the Trooper's electrical system. If you're good with those kind of mods, it would probably make a good runner. The aluminum heads do breathe better than the iron heads used in the TBI 2.8. However, those heads have the intake flanges machined at a different angle, which is not compatible with the Old-School 2.8 TBI intake. If only it were so easy! So if you use aluminum heads on any of these swaps, you're pretty much stuck with whatever MPFI system that particular engine came with.

I found specs for your 3.4, 180 hp @ 5200 rpm and 205 lb-ft @ 4000 rpm. So, it's a good, torquey engine.

However, there's an alternative that is almost a bolt-in. Use a '93-'95 3.4 Camaro/Firebird "F-Body" 3.4. The block will bolt right into a 2.8 Trooper with just some very minor mods. If you recondition the 2.8's heads, or get heads with an F-Body 3.4, the 2.8 TBI intake will bolt right up. With performance exhaust, a TBI with larger-throats and intake holes bored-out to match the TBI's larger bores, and a few performance "goodies", the ol' iron-head engine will put out at least 180hp and pretty close to 200 ft-lbs torque.

The MPFI Impala 3.4 is gonna have better driveability, and probably will get better mpg, just due to the improvements made over the years.

You do have even more options, with your parts engine. If you were find a good/boreable 3.4 F-Body block, you can take the crankshaft and conn rods out of your Impala 3.4 and use them for an iron-head build. You'll need to run the same pistons they used with the F-Bodies. For a nominal fee you can have the F-Body pistons pressed onto your 3.4's rods.

So you don't need an entire engine, just a block to build. Conversely, I have no idea if you could bolt the old iron heads onto your 3.4, seems like a step backwards but if so, you could probably change pistons and use that block instead. One way would be to compare head gaskets for your engine, to those for a '95 Camaro 3.4. Rockauto.com is a great place to look up parts.

It might be a case of pulling the old 2.8 and doing a side-by-side comparison to see how they differ. One advantage your Impala block has, is that the starter is already on the correct side to mate up with the MUA5 transmission (ends up being on the driver's side in an RWD application). The F-Body block has a right-side-mounted starter, and you must drill holes in the driver's side of the engine to accept a FWD starter. Never Fear, Rodney Dickman Fieros sells a drill/drilling jig/tap kit for under $100 that makes the job a cinch. I drilled mine free-hand, and it was NOT a cinch, I can tell you that!! :shock:

Anyway, just a few high points, no doubt there will be other issues to hurdle. There are a few Trooper Dudes here contemplating doing a "3500 hybrid" which apparently is a popular mod. Use the Search feature here to find those threads and more.

The GM V6-60 Degree forum has a bunch of good info about "3x00" swaps, so you might want to check them out.

http://www.60degreev6.com/vb5/forum/aff ... 00swap-com

A bunch of info there about "3400 hybrid" builds as well.

BTW I have a collection of info regarding the 2.8-to-3.4 swap, it might give you some insight on doing an iron-head swap. I've been very happy with mine, did the swap in 2002 and it's still running great. Even better without a battery that had a dead cell; with the new battery, it's like driving a new rig all over again!

If you're interested in that swap info, drop me a line here via Private Message. Be sure to include your email address, and I'll forward the files to you.

HTH, Happy Swapping, and Welcome to the Planet!..........ed
'90 3.4 Troop LS;
'89 Troop RS (Exhaust Valve Challenged), now gone to a Good Home!
Yes, I am a Trooper-Holic!!!
Keep On Troopin' !
Ed Mc.
I am the Stig
Posts: 4243
Joined: Thu Aug 14, 2003 1:26 am
Location: Poulsbo, WA
Has thanked: 6 times
Have thanks: 405 times

Who is online

Users browsing this forum: No registered users and 9 guests