99 7.4 cam replacement

[BowtieBrody]

I read a review on the trucks that was published circa 1995. Apparently GM knew exactly what they were doing by setting conservative timing and retarding the camshaft. Apparently it was done for "operator comfort" and to "reduce engine noise" which I think worked very well. A stock LS engine sounds much more like a V8 than a stock L29 which is horribly disappointing (and yes I do realize I'm not exactly comparing apples to apples here...). Leave it to GM to take what could have been an absolute monster of an engine which is capable of much more power than they were willing to give it, and choke it down to a neutered lap dog. Meager and unreliable 19lb injectors, conservative ignition timing, retarded cam timing, non adjustable rocker arms, and the most obstructive exhaust system known to man handicapped this truck beyond belief. I'm sure I'm missing one other thing they did to screw it up too.

Another hiccup is that the heads are cast as is, so it's a rough finish, from a little research there are these so called "Ski Jumps" in the heads that are there to try and build torque, but in reality really hurt performance; that's why I'm going to have at least $1800 in head work alone with rebuilding, porting, polishing, and smoothing out those ramps when it comes time to rebuild my engine.

This article here kind of delves into making the Vortec 454 the powerhouse it should've been from the start.
http://www.trucktrend.com/how-to/engine/0510st-1996-chevy-truck-vortec-big-block/

 

[Supercharged111]

All easy fixes. I sure hope a new muffler makes a difference on this thing because I'm going to have to live with the stock manifolds a bit longer. I can only spend money as fast as I make it and that 411 swap is just begging to be done. I dunno about the rest of you, but I absolutely HATE the way this truck shifts. Way late upshifts and over eager downshifts have this thing needlessly screaming any time I want to accelerate. I'm confident there is 500ft/lb to be had NA but stock I really don't even feel the 400 they claim.

 

[BowtieBrody]

All easy fixes. I sure hope a new muffler makes a difference on this thing because I'm going to have to live with the stock manifolds a bit longer. I can only spend money as fast as I make it and that 411 swap is just begging to be done. I dunno about the rest of you, but I absolutely HATE the way this truck shifts. Way late upshifts and over eager downshifts have this thing needlessly screaming any time I want to accelerate. I'm confident there is 500ft/lb to be had NA but stock I really don't even feel the 400 they claim.

I know taking off the crappy Thrush or Flowmaster muffler and welding in a Jones straight through internal X muffler woke my truck up a little bit, I wish mine still had the stock exhaust when I bought it so I'd really be able to tell the performance difference.
I've never really noticed the shifting, my truck pretty much drops down a gear and eats any time I get on it.

 

[Supercharged111]

Another hiccup is that the heads are cast as is, so it's a rough finish, from a little research there are these so called "Ski Jumps" in the heads that are there to try and build torque, but in reality really hurt performance; that's why I'm going to have at least $1800 in head work alone with rebuilding, porting, polishing, and smoothing out those ramps when it comes time to rebuild my engine.

This article here kind of delves into making the Vortec 454 the powerhouse it should've been from the start.
http://www.trucktrend.com/how-to/engine/0510st-1996-chevy-truck-vortec-big-block/

Strange that the 96 had the TBI cam. A 5.7 Vortec will put down 190-200hp stock.

 

[Supercharged111]

I know taking off the crappy Thrush or Flowmaster muffler and welding in a Jones straight through internal X muffler woke my truck up a little bit, I wish mine still had the stock exhaust when I bought it so I'd really be able to tell the performance difference.
I've never really noticed the shifting, my truck pretty much drops down a gear and eats any time I get on it.

Does it shift worlds different than your Burb did? I've never owned a vehicle with a shifting strategy like this one has.

 

[BowtieBrody]

Strange that the 96 had the TBI cam. A 5.7 Vortec will put down 190-200hp stock.

I read somewhere that some early 96 trucks had TBI cams and valvetrains, these were kind of oddball trucks, I don't remember the exact production number off the top of my head; I'll have to do some digging in my saved documents to see if I can find it.

Does it shift worlds different than your Burb did? I've never owned a vehicle with a shifting strategy like this one has.

It's a noticeable difference, my Burb kind of hunted for gears, it'd dig in, bog down, shift and scream into the next gear. Maybe someone messed with shift firmness on your stock PCM when they wired and plumped up the Whipple?

 

[Tom P]

I know taking off the crappy Thrush or Flowmaster muffler and welding in a Jones straight through internal X muffler woke my truck up a little bit, I wish mine still had the stock exhaust when I bought it so I'd really be able to tell the performance difference.
I've never really noticed the shifting, my truck pretty much drops down a gear and eats any time I get on it.

Believe me, going from a stock muffler to jones max flow 22" and a single 3" tail pipe made a world of difference. To me it was like driving a truck with the 4.3 and then driving the same truck with a 5.7. Not blow you out of your seat different but I could finally do dually burnouts afterward...

 

[Supercharged111]

I'm going to try a Walker bus muffler, dual 2.75" in and single 4" out. Hoping to keep this thing quiet. Diamondeye makes a 4" diesel tailpipe so it ought to go together nice.

 

[Tom P]

I don't know how quiet you want to keep it but consider the jones max flow. My truck is not loud. It has a good tone and you can hear it in the cab but I definitely don't wake up the neighborhood when I leave for work at 6:00am

 

[Supercharged111]

Aren't those like a Magnaflow knockoff?