transmission fit?

[292farmer]

i was looking at the vortec 4200 inline 6 and came across this site, which as u see the clip i copied states that it shares the chevy v8 pattern, they didnt say the vortec v8 pattern or gen 1 sbc, is their a difference? if not does that mean it will bolt up to the sm465in my 1972 c20? thought it'd be a neat upgrade for 292 inline in it, i looked at a company that will redo the wiring to work in a older vehicle and fix the theft preventative code(think thats what its called cant remember) figured have to definitely custom make motor mounts. and maybe some radiator moving and firewall fitting but i dont see it being to different in size from the 292. anyone see a possible catch i missed in swapping it in?

http://www.novak-adapt.com/knowledge...es_general.htm

Individuals swapping these into Jeeps should understand that they share the same Chevrolet V8 pattern, and will marry to a Jeep or GM transmission accordingly.

[airdale94]

The only thing I could seee would be the flywheel. Unless they put manual trans. behind them you would have to see if a V-6 or V-8 would fit.

[292farmer]

thanks for your thoughts, they put the manual trans behind the 2.84cyl and 3.5/3.7inline 5 in the Colorado and canyon, which were the same motor just minus 1 or 2 cylinders part of the atlas series of motors. so i'm hoping to use that flywheel and just have it rebalanced. and i guess the automatic and manual bellhousing is the same i'm told they just have plates that come off it. maybe a 4.3 flywheel but i would imagine the inline 5's would work.

[AusTruck]

Just an FYI. I have one of the 4.2L Vortec 6-cylinders in my '03 Trailblazer and I'm pretty impressed with the engine. Surprising amount of hp and torque, and I can get 20+ mpg on the highway with the AC off.

I've always wondered why these engines weren't embraced for performance use. One reason may be that they are stroker engines, where the bore is smaller than the stroke. That usually isn't the best formula for performance. There was a guy who put one in a ~50s Chevy truck and added a turbocharger that I saw on youtube a while back. Sounded very good in the vid.

I remember being at SEMA a few yrs ago and asking one of the Chevy engineers why they didn't do more, as far as GM Performance parts stuff, with this engine. I got back a blank stare.

One other thing after I noticed you're in NH. The GM guy did say that the 4.2 was one of the fastest warming up engines GM ever created.

[292farmer]

the main reason theirs no real performance upgrades is they are overlooked due to the 5.3v8s and the i-5 in the canyon/colorados had a head issue first few years, due to basically taking 4.2 and chopping off a cylinder they had some sealing problems and valvtrain stabilty and longevity. seemed to have given some people a scare and their complex. i do know they make headers intakes and have performance chips and ive seen someone dynoed his with a header coldair intake and jet stage 2 chip and made 260rwhp and 270rwtq which i believe is about 310hp and 320tq at crank, they are kinda put into heavy vehicles trailblazer is about 4500-5000lbs depending on package. so they seem slow sometimes so people feel its not worth it but they only have 3.73 as the lowest gear, usaully a 3.42 so that hurts performance too. and the 4 valves per cylinder makes up for the small bore allows more cfm then a comparable 2 vavles per cylinder in small bore vehicles thats what ive been told at least but that was my buddy on his 4cylinder.

[68gmsee]

My .02

Since you'll be going down in cubic inches from 292 to about 255, and since your 292 is a workhorse with a lot of torque, you may be disappointed. Might be better off with a 350 on that C20.

I have a trailblazer with the same engine and I like it, however it doesn't compare in power to my old 96 Tahoe with a 350. The mpg on the highway with the Tahoe was about 20 (I squeezed 22 mpg once). With my TB the max I've gotten is 21 and it's smaller in size and weight with less power.

Another thing to consider re: mpg is our trucks are not very aerodynamic so you may only see a small increase with the 4.2 but less torque for pulling.

[292farmer]

true i thought of that, i am keeping the 456 gears should help, i may never do this either im toying with the idea, plus the allure was it was a inline 6 modernized. plus once i do get to it im sure the market will have produced more performance parts that will fill the gap for the need for more low end torque this 4.2 does make 90% of its torque from 1600-4000rpm so its still a low end motor just the fact it revs almost double the rpm range makes it less of a torque appearing maonster the 292 is. i figure between the 456 gears and the sm465 i shouldnt lose much in the way of hauling power and towing, and im under no illusions that motor will be amazingly better then the 292, i was just hoping to moderize the motor but keep the 6cyl faith, mpg wise im hitting 17-19 now so im happy with the 292, just maybe want something different, i may find another vehicle for this swap idk. sorry this was so long thanks everyone

[292farmer]

maybe ill get this, im trying to get the price from the guy rite now. and put the 4.2 vortec in this to test how i like it plus if i have to do frame and firewall changes im not doing it to my good one now. this truck actually used to be used at whitcombs concrete my dad used to work their im gonna ask if he remembers it.