Checked around here. A 4200 engine is $1400 to $1800. What are things I will need? Gas pedal, wiring harness, computer,transmission. How big of a radiator will I need. What kind of fuel pump will I need. What kind fuel pressures? Thank y'all again!

FYI, for radiator, i contacted be-cool customer support with dimensions of core and mounting holes. They provided a P/N and CAD drawing. Mounted firs try with zero modifications. I think you’ll find it hard to find an aftermarket radiator that cannot handle the big 6.

Gas pedal - yes
Wiring harness - yes - including the body harness from the PCM into the cab upto the gas pedal and the diagnostic port and if you can upto the gage cluster.
PCM yes
Transmission - depends if you want to run the 4L60E

Best to run an in tank EFI pump - a walbro pump for a grand national is good enough.

Fuel pressure 58 PSI for a return less system (04 and up engines)

Some have swapped the return less fuel rail to the 02/03 return style and run an external fuel pressure regulator.

Rad - go look at the size of a stock trailblazer rad.

Efi-Diy do you have the part #for the kit to remove broken head bolts? Is there a fix for the head burning valves? Does anybody have a video of your 4200 running with different cams? Who is messing with the 4200 here? Do y'all have any pictures.

Here is Efi-Diy's truck on the dyno. HERE!

A few more videos.
350 HP with just cams and mild porting!

Stock engine with 8 psi boost!

350 horse video is showing witchy woman by the Eagles. Did a little searching, the valves are chrome plated. Can I upgrade to stainless steel valves and will that help with the burning of the valves?

Burning the valves isn't typically an issue, but yes, you can always upgrade to them if you feel its necessary. For high boost it would be advisable.

Here's the right link for the 4200/350 HP dyno test.

Try this one!

Not many reports of burnt valves on the 4200 - maybe that fuel injector is partially plugged and that cylinder ran hot.

Drill J42385-402
tap J 42385-403
installation driver J 42385-404
alignment pin J 42385-303
bushing J 42385--302
bolts J 42385-421
fixture plate J 42385-401

One guy recently was able to get the busted bolts out using a reverse twist drill bit.

You find more pictures on the 4200 site.

Thank y'all!

Ok got all the broken head bolts out. Now what? Rebuild stock/freshing up or what. Just want a good street car. What needs to be done to the head?

So you're back on the 4200 instead of the 292? Basic multi-angle valve job to the head and light porting would help. Are you planning to go turbo?

I'm working on all of it a little at a time. Yes would love to turbocharge it.

Which year 4200 are you working with?

If your starting with an 2002 -2005 - try and find a 2006 up head/cam cover/ignition coils/VVT/exhaust manifold.

In either case port the head - especially on the exhaust side. If starting with an 2002-2005 replace the valves/seats with ones from the 2006 up head - they are 1mm bigger OD.

The intake port just needs a blend on the short side to eliminate the sharp edge (once the heads apart -its sticks out like a sore thumb) and blend in the pocket. The exhaust side needs work, count on 3 hours/port. From the seat to the port exit needs work. GM did this for emissions. Once ported the exhaust flow will increase by almost 45% on a late head.

If your going turbo and using the stock internals:

Open the top ring gap to about 0.016/0.019".

Assemble the rods with new 10 under bearings and accurately measure the inside bearing dia. Get the crank turned 10 under for 0.018/0.0021 rod bearing clearance. The mains are fine at stock clearance.

Shim the stock oil pump relief spring about 3/32".

Route oil from on the oil filter outlet to the main oil gallery via the external oil plugs on the pass. side of the block. I have the needed -8 fittings to do this.

I have a 06 engine!!

Thank you efi-diy!!

It is an 06 engine it had a burnt valve. I have to get a computer and transmission now and any missing parts.

Really wished someone still made the flywheel that bolted to the 4200 ,i have a Colorado 5 speed transmission ,but ive looked and called alot of places,but so far one place but cost way too much ,i had plans to run it in a 93' 300zx ,but its been holding me back

Which place did you get a price from and how much was it?

Man its been a while,i called a bunch places ,but it was high in the 800 range ,a fair price to me ,imo would be 3.5-500 ,im almost tempted to sell it and just find 3.5 or 3.7 of a colorado

check the flywheel sign up list on vortec4200.com

I have an account there that i made like two years ago ,i never got an email from the admins approving it so its still inactive ,i made another account yesterday same story ,i got an email just saying welcome from a admin Pete ,still cant log in

I've looked and looked for the width of the 4200 to see if it would fit in a 1937 Chevy truck. Does anyone know if anyone has tried that swap? The length and height are good but I hear the widest part is the power steering pump. The 37 engine compartment gets wider as it goes back so maybe a Vortec I5 would be a better choice if the 4200 is too wide.

Any thoughts? Is there a source for dimensions that include the width of the accessories?

I can measure and let you know.

from crank centerline:

outside of PS pulley 11 3/4"

outside of the alternator body 12 1/2

all measurements +/- 1/8"

The original p/s reservoir extends ~ 4" past the outside edge of the PS pulley - but the pump itself is common to many 2000 up GM products - and can be swapped for a pump (change the pulley) out of a vehicle that has a remote mount reservoir.

If the engine compartments are similar in width between a 47-55 and the 37 - then it will fit.

efi-dyi,
Thanks for taking the time. I'm really looking hard at that particular swap.

I just remounted the 4200/trans in my 51 - about 3/4" farther forward and 3/4" high to gain room at the back of the engine for the one off intake manifold. So I'll be finding out pretty quick if the inner fenders are going to need a relief added.

Just a note the stock intake has an sound insulation pack around the actual intake and can be removed to ease clearance + improve visual look.

efi-diy,
I measured the engine compartment of my '37 and that 4.2 might just fit but, if so, barely. Could you measure from the back of the block/head to the belts on the alternator/power steering? Also, the width of the cylinder head ( the fire wall has a concave section in the middle for engine clearance but the 4.2 looks really wide). The inner fenders angle out as they go back so I gain clearance the shorter the engine is. Ultimately, I may have to go with the I5.

Thanks,
Dave

head is 10 1/4 wide
Trans flange to the front edge of the pulley (PS) 25 1/4" -0/+ 1/4"