GM 4.2 has anyone done it? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**steelhorse** · 06-13-2011, 08:54 AM

As the title says,has anyone put a new GM4.2 in their truck?Seems like it would be a great canidate for a turbo build.

**JJorgensen52** · 06-13-2011, 09:42 AM

Turbo has been done in the Colorado/Canyon platform, I think there is a whole kit for it available

That said, haven't seen one in a truck but I've thought about it - they're a phenomenal motor.

**Boog** · 06-13-2011, 09:49 AM

Didn't GM build a straight 5 cylinder and put it in the trailblazer some years back? Or is this the 4.2?

usmcchevy · 06-13-2011, 10:08 AM

4.2 is the 6 cylinder
3.5/3.7 is the 5 cylinder

I think what holds people back from doing the 4.2 swap is the fact that they can get and install a 4.8 or 5.3 for about the same money.

**steelhorse** · 06-13-2011, 10:04 AM

I think the 4.2 is a 5cyl.

406 Q-ship · 06-13-2011, 10:12 AM

The electronics on the 3.5/3.7/4.2 inlines is ALOT more complicated compared to the LS series of engines.

hugger6933 · 06-13-2011, 11:56 AM

Turbo's have been done. I think one guy did one in a 66 chevy two. The eletronics are a lot more coplacated also as said above the atlas platform is what the General calls them the 2.8 4- 3.5 3.7-5 and the 4.2-6 . Are good motors all but not without their problems. The wiring would probably double the cost of a ls buiuld and them there is the oil pan. on some models [4x4] the front differentail goes thru the oil pan. I'm sure custom pans could be had from someone but there again is more cost. Jim

Ackattack · 06-13-2011, 12:55 PM

I have thought of building a Nova with a 4.2L in it (turboed eventually too) but haven't gotten there.

I was doing some looking into it, and the 4.2L really don't get any better gas mileage than the 5.3L (in a trailblazer) so I was kinda disappointed about that. I thought it my be a more "economical" engine. However, I think it would definatly add to the uniqueness factor. Especially if it was in an original 6 cylinder car/truck.

It will be many years until I get around to building a nova though. My next build is going to be a 6 cylinder though....but a 5.9L cummins in a suburban

06-13-2011, 08:54 AM	#1
steelhorse Senior Member Join Date: Apr 2008 Location: Franklinton NC Posts: 1,309	GM 4.2 has anyone done it? As the title says,has anyone put a new GM4.2 in their truck?Seems like it would be a great canidate for a turbo build.

06-13-2011, 09:42 AM	#2
JJorgensen52 Simple? What's simple? Join Date: Apr 2007 Location: Southeast CT Posts: 1,472	Re: GM 4.2 has anyone done it? Turbo has been done in the Colorado/Canyon platform, I think there is a whole kit for it available That said, haven't seen one in a truck but I've thought about it - they're a phenomenal motor. __________________ CURRENT '50 GMC 100 shortbed Gen IV 4.8 LS - 4L65E (Secret truck, Shhh!!!) Build '63 Buick Wildcat Coupe 401ci Nailhead (Very much in pieces) Photos '66 Impala SS convertible 327-QJet-glide (4 speed swap one of these days...) Photos '69 CST/10 4x4 SWB Stepper 350 2bbl - NV4500/NP241C (Broken Truck!) '72 Sierra Grande 2WD LWB fleetside 350-TH350 Refresh '99 K2500 Silverado RCLB 5.7 Vortec - NV4500/NP241C (Daily) '99 K2500 Suburban 7.4 Vortec - NV4500/NP246 (still working out the bugs) SOLD '71 Custom/10 2WD LWB fleetside - '72 GMC K/3500 Dually (Sold to redryder)

06-13-2011, 09:49 AM	#3
Boog laying low Join Date: Mar 2001 Location: Searcy, Ark. USA Posts: 13,514	Re: GM 4.2 has anyone done it? Didn't GM build a straight 5 cylinder and put it in the trailblazer some years back? Or is this the 4.2? __________________ Boog 69 Chevy stepside, 358/T350, 4.11 posi, 4.5/4 drop, rallys, poboy driver primer is finer 91 Chevy sportside, Tahoe, Yukon & GMC Crewcab All GM..'nuff said. I stand for the flag and kneel at the cross

06-13-2011, 10:08 AM	#4
usmcchevy Has more rust than truck... Join Date: Apr 2005 Location: Ivanhoe, MN Posts: 2,421	Re: GM 4.2 has anyone done it? 4.2 is the 6 cylinder 3.5/3.7 is the 5 cylinder I think what holds people back from doing the 4.2 swap is the fact that they can get and install a 4.8 or 5.3 for about the same money. __________________ 1972 Custom/10 SWB, 4.8/4l80e Build thread LSx Swap FAQ index

06-13-2011, 10:04 AM	#5
steelhorse Senior Member Join Date: Apr 2008 Location: Franklinton NC Posts: 1,309	Re: GM 4.2 has anyone done it? I think the 4.2 is a 5cyl.

06-13-2011, 10:12 AM	#6
406 Q-ship Registered User Join Date: Oct 2010 Location: Largo Florida Posts: 632	Re: GM 4.2 has anyone done it? The electronics on the 3.5/3.7/4.2 inlines is ALOT more complicated compared to the LS series of engines. __________________ Lifes journey is not to arrive at the gate well preserved, it is to slide in sideways all used up and wore out yelling.....God what'a ride! Where patience fails, force prevails Stapp's Ironical Paradox "The universal aptitude for ineptitude makes any human accomplishment an incredible miracle."

06-13-2011, 11:56 AM	#7
hugger6933 Registered User Join Date: Oct 2008 Location: Marianna Arkansas Posts: 7,280	Re: GM 4.2 has anyone done it? Turbo's have been done. I think one guy did one in a 66 chevy two. The eletronics are a lot more coplacated also as said above the atlas platform is what the General calls them the 2.8 4- 3.5 3.7-5 and the 4.2-6 . Are good motors all but not without their problems. The wiring would probably double the cost of a ls buiuld and them there is the oil pan. on some models [4x4] the front differentail goes thru the oil pan. I'm sure custom pans could be had from someone but there again is more cost. Jim

06-13-2011, 12:55 PM	#8
Ackattack Senior Member Join Date: Aug 2002 Location: Valley Center KS Posts: 3,524	Re: GM 4.2 has anyone done it? I have thought of building a Nova with a 4.2L in it (turboed eventually too) but haven't gotten there. I was doing some looking into it, and the 4.2L really don't get any better gas mileage than the 5.3L (in a trailblazer) so I was kinda disappointed about that. I thought it my be a more "economical" engine. However, I think it would definatly add to the uniqueness factor. Especially if it was in an original 6 cylinder car/truck. It will be many years until I get around to building a nova though. My next build is going to be a 6 cylinder though....but a 5.9L cummins in a suburban __________________ Project Bruiser: 68 Pro-Touring C-10 5.3L / 4L60E Project Ironhide: 97 GMC Crew Cab 4x4 Cummins SOLD: '69 GMC 1/2T SWB TBI'd: Project No Buck Assembly Manual Index Sign up Thread!!! Factory Service Manual Index



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