'96 454

[53burb]

Another deal just popped up. A guy has a '96 454 with all the FI stuff except computer & wire harness. According to my other thread, the Vortec heads will not fit, but all the FI stuff should. This 454 would need to be rebuilt...what do u think??? http://phoenix.craigslist.org/pts/317911148.html

[rage'nrat638]

looks great if you need one and got the cash..

the efi is big money..hope you can get the computer and harnesses

[Bob B.]

A '96 should be a Vortec 7400. That is a Mark VI, and they have good heads on them right from the factory. Rectangle port with a swirl type combustion chamber. Much better that the Mark IV and V 454 'peanut' truck heads. It is the '91 to '95 Mark V's that have the heads that will not interchange with any other big block.

[53burb]

Thanks guys for your help, I'm sure you are tired of my everchanging engine decisions.....BTW, this is a roller block, right???? Also, the serpentine system will bolt right onto the '96, right?? The engine/tranny harness is $700, not to mention the computer, fuel pump, etc....

[Bob B.]

A '96 should have a roller cam. The '96 trucks had serpentine belts, but the A/C compressor and alternator were on different sides than a earlier truck.

[53burb]

It should still bolt up, right?? Bob, I see in your signature that you have this engine, also the same tranny that I will be using. How do like the setup?? Any performance mods or suggestions??

[Bob B.]

I think the Vortec 7400 was one of the best all-around truck big blocks. Very smooth, plenty of power, and very reliable. As for your accesory mounting, starting in '96 GM changed the A/C compressor. The '95 and older trucks used the R-4 type compressor. I am pretty sure the accessory drives from an older 454 will bolt up to a Vortec 454, but you might have some clearance issues with the A/C compressor, due to the Vortec's large intake manifold. I have not tried it, so I don't know for sure.

[53burb]

I picked up the engine yesterday. I think I love it...My computer at home is screwed up for right now, so I can't send any pics. I think all I have planned is a stock rebuild, custom chip, headers, & cam. Anybody know the stock specs of this engine??

[Zoomad75]

If it's a L29 (which I assume it is for 96) it's rated at 290 hp at 4200 rpm and 410 lb/ft or toque at 3200 rpm. C.R. is 8.91. It is a hydraulic Roller cam too. I don't have the stock cam specs though.

That 290 hp is a "net" rating, meaning it was taken with the full amount of accessories (w/p, p/s, a/c, ect) on at the time of testing.

A little known fact the L29 intake is a two piece design that the lower half is the base for the injection setup on the Big Block Ramjet. They just used a "cooler" looking upper plenum instead of the stock L29 part.

If you want to simplify the electronics, get a harness and computer for a ramjet and have it programmed to your specs by Arizona Speed and Marine. Instead of trying to make the stock PCM work (including the stupid passlock theft deterent system) you can get the basic engine harness that has only what you need. The ramjet harness uses the stock L29 sensors to operate and plugs right into them. It's a much easier way to go if you want to keep the injection.

[53burb]

It is an L-29. Here is the Mortec description: 10237297...454.......96-up...4-bolt, Vortec 7400", "L-29" Gen.VI Thanks for the info on the harness. I did not know that the Ramjet 502 was almost identical to this engine....If I go this route, I still need a harness for the tranny. The tranny is a 4L80E. Any info on this to plug into the PCM from a RamJet??

[Zoomad75]

53burb-

I didn't say the 502 ramjet was almost identical, just that they used the lower intake manifold from the L29. Everything else on the 502 was set up for it. I assume they took the L29 lower intake to save time on the engineering side.

That being said the sensors are the same also. So the TPS, map, coolant temp will all work with the Ramjet. DirtyLarry is another member here who has a L29 intake he is planning to install onto his 454 in his 78 k10. Between the two of us and some people we know through work we figured out the compatibility to the Ramjet system. Mainly is becuse the L29 was used in marine applications. The Marine engine controller is the same part thats used on the ramjet crates (big or small block). Arizona speed and Marine can flash the marine/ramjet controller to your specs. You can get the ramjet wiring harness and controller from GM. Look on Scoggin Dickey's website for the ramjet parts, but the wiring harness is 12499117 and the controller is 88962718. Or I think you can buy the controller from Ariziona speed and marine too.

As far as the tranny goes, you can get a standalone Controller and harness from TCI. I think that's where you might have to look at the cost to compare the Ramjet parts with the additional cost of the standalone Trans computer/harness versus the oem harness and PCM that could control both. The pro to the stock PCM and harness is that it will run both the engine and tranny together. The cons are the added complexity to the wiring for all the stuff you won't need on an older vehicle. If you aren't afraid of the wiring challenge you can save a few bucks. If time is worth money and don't want the stress of reducing a stock harness down to what you need then the aftermarket stuff would simplify things greatly. Another thing to look at is how to diagnose/tune either setup. If you run the stock setup you'll need a tech 2 or equivelent scanner. The aftermarket stuff you can usually get by with laptop based software (some of which can access some of the stock PCM functions too).

You could also look at 96-98 Chevy P-chassis RV's as they used the L29/4L80 combo as did Workhorse Custom Chassis when they took over the P-chassis in 99 and used the L29 up to the 2000 model year. Given the amount of RV's down in AZ there might be some in the boneyards to pull from. Reason I mention the RV side is the wiring for the engine is somewhat simplified for them as they don't have all the interior crap tied into the harness. They aren't as simple as the Ramjet stuff, but not as overloaded with crap as the trucks were. That is depending on what the RV manufacturer might have done to it.

[53burb]

This is the harness I was planning on getting. It is the TH-100. Anybody know a cheaper route that controls both the tranny & engine together?? BTW, thanks Rob Z. for the above info. http://www.thedetailzone.com/TBI%20FI.htm