Vannin' Home Forums General Discussion Readers Rides 1997 Chevy Express Cobra Conversion

This is really coming together. Nice work

Have been slowly working on it. Managed to get the new muffler and tailpipe fit yesterday afternoon. Snagged a Walker Quietflow SS and matching 4" tailpipe for a 2001-2006 3500HD with a 6.0L or 8.1L from Summits scratch and dent clearence area. Fit the 97 Van like it was made for it. Muffler is dual 3" in, single 3" out and the tailpipe is 4" but necks down to 3 where it slides into the muffler.













https://youtu.be/zJBiw3xkiYY

https://youtu.be/bq8CAvqnubU

Nice

Nice work

Just caught up on the van. Awesome work! I installed the same head unit in my 05 Safari. Had to move everything from around the dash. It was alot of work but I loved it. Sold the van but kept the head unit and dash trim to put into my 98 astro.
Was thinking about putting in the Express. But not sure if I want to do it the same as I did the first time. I hate have to take that whole dash panel off every time I need to get in there. Dont want to say it, but I like the way Ford radios come out.

Made alot of headway and it is driveable now. After street tuning I dialed in the 383 on a chassis dyno. It made 383 hp and 399 tq uncorrected and 412 hp and 431 tq std corrected on a 102F day. Peak torque happened at 3,100 rpm and peak hp was 5,600. I need to change the fuel pump so that I can dial it in on E85, its begging for higher octane and more timing. I made peak power with a very conservative advance curve and 91 octane.

I flushed the ac system, changed the compressor to a Sanden 4261, swapped in a parallel flow replacement condenser and went with a variable orifice tube up front from Rockauto. I added a PCM controlled 16" 3,000 cfm puller and a cutdown Duramax fan on a Trailblazer SS thermal fan clutch. Went back to a stock radiator and an 01-02 fan shroud. Really made everything fit better. Using a factory 01+ Donaldson designed GM air cleaner housing and it is plumbed with a 4" intake and 102mm cartridge style LS3/LS7 MAF. I get 41°F air out of the left vent at idle in 102F temps and the engine stays around 185°F. I recently updated the fan clutch to an electronically controlled clutch. The clutch fan is on the PCM fan 2 output via a relay that supplies it 12v. When the engine first starts and the interior is hot the fan clutch locks up and really drops the ac pressures, then as the interior cools down and the pressures drop the mechanical fan returns back to the lower rpm setting. If it warms up to 189F the clutch is locked in. It usually holds around 185F with the clutch released and the 3,000 cfm electric on.

Currently waiting on an all aluminum replacement radiator from California. To replace the almost new TYC OE replacement thats core exploded. I installed my all NOS GM headlights, turn signals, side markers and reflectors up front along with finished my exterior LED conversion. Including the headlights and all exterior lights except the turn signals and brake lights that are a momentary use the exterior lighting draws 4.7 amps. 4 HI headlight mod incuded for extra light. Now on to the customizing the Kodiak K&N heatshield so that it clears the hood.

Yes, Sir. What he said was,
You cant spell Express without SS.