'99 Vortec truck w/454, but want a 502: Need help...

[Chevy454]

A buddy has a '99 3500HD dually, 5-speed manual I believe...and the Vortec 454 has 225k miles and is about to take a crap...darn good truck otherwise. Anyway, he's wanting to put a crate engine in it, and saw that the 502 wasn't much more than the 454...and he pulls a backhoe with this truck, so he needs all the b@lls he can get. Anyway, is this a pretty straightforward swap? Will the fuel injection setup support the 502??

[EFI69Cam]

A buddy has a '99 3500HD dually, 5-speed manual I believe...and the Vortec 454 has 225k miles and is about to take a crap...darn good truck otherwise. Anyway, he's wanting to put a crate engine in it, and saw that the 502 wasn't much more than the 454...and he pulls a backhoe with this truck, so he needs all the b@lls he can get. Anyway, is this a pretty straightforward swap? Will the fuel injection setup support the 502??

Yes it will, but would need upgraded injectors, tune and probably would nose over at 3500. The vortec manifold is not the best.

[BB69]

Not to hijack the thread, but I am in the process of trying to convert my Vette to fuel injection. I am looking for a port injection manifold. Is the 454 manifold port injection, or throttle body injection? Also, is it cast iron or aluminum. I have been searching the net for these answers without much luck.

Thanks
Ken

[EFI69Cam]

The 91-95 truck 454s are TBI, the 96-2000 are port injected.

like I said above the manifold is a low end torque biased design, its alot like the TPI on a 350. Made great low end, but nosed over pretty quick.

[BB69]

When you say nosed over pretty quick, what kind of RPM are you talking about? The setup I have now dies at about 5200RPM. I am running a small cam (.510/.515 lift), stock heads, and stock 2" exhaust. I'm not looking for a high RPM manifold. Do you know if the port manifold is iron or aluminum?

Thanks again.
Ken

[EFI69Cam]

When you say nosed over pretty quick, what kind of RPM are you talking about? The setup I have now dies at about 5200RPM. I am running a small cam (.510/.515 lift), stock heads, and stock 2" exhaust. I'm not looking for a high RPM manifold. Do you know if the port manifold is iron or aluminum?

Thanks again.
Ken


The 99 'burb I had with the 454 ran out at 4500.

The manifold is aluminum, uses a plasic fuel rail and a vortec/ls1 throttle body with cable control. It consists of a lower and upper half, with a central plenum and fairly long runners.
I have a vortec 454 that I am installing in my 91 K5 Jimmy. Its a truck motor without a doubt.

If you want a TPI style intake that makes decent power look at the Arizona Speed and Marine BBC TPI. This is manifold I am using on my 69 Camaro. It is based off the Lingenfelter designed Mercury Racing off-shore competition manifold. It is more like a Accel Super Ram, which makes good power down low, but does not nose over like a factory TPI.

www.arizonaspeed.com
just don't buy their electronics.

[BB69]

I've taken a look at their manifold, and the problem is fitting it under the Vette hood. The hood is so low I can't fit any of the aftermarket TPI manifolds. The Holley one is about 4" taller than my stock manifold. That is the main reason I was looking for the stock truck manifold. I was hoping it was shorter.

Thanks
Ken

[EFI69Cam]

I've taken a look at their manifold, and the problem is fitting it under the Vette hood. The hood is so low I can't fit any of the aftermarket TPI manifolds. The Holley one is about 4" taller than my stock manifold. That is the main reason I was looking for the stock truck manifold. I was hoping it was shorter.

Thanks
Ken


I got mine cut down 3/8" and the angle put on the TB flange so the TB mounts at a downward angle. It fits under a cowl hood on a 69 Camaro, is there less room under a vette hood?

[BB69]

I have a 69 Camaro and the Vette, both with big blocks. My Camaro has a flat hood, and there is plenty of room for the Performer manifold. On the Vette, the stock low rise manifold needs a drop base filter to clear the hood. The Vette has much less room than the Camaro. I am always amazed seeing the difference in height of the two cars. I could use the L88 hood for the Vette, but the wife hates it. It's also expensive and would require paint to boot. Do you have any idea how high the truck manifold is?

Thanks
Ken

[EFI69Cam]

I'll measure it for you.

[Chevy454]

Ok...so my buddy will need to swap to a decent intake when he swaps in the 502? What about getting the fuel system & ecm to jive with the 502?

[USAZR1]

Ok...so my buddy will need to swap to a decent intake when he swaps in the 502? What about getting the fuel system & ecm to jive with the 502?

I've got a Mercruiser TPI set-up for a 502" that is just sitting in my garage,waiting for a new home. It looks kinda similar to the AZ Speed & Marine unit and would probably work great on a truck application. It probably needs an ecm and fuel rails.
Drop me a line,if interested.

[Ron S]

That manifold is really kinda weird with the injectors and rails on the inside,if its the one i'm thinking of.The problem is the pcm is not the same as an ls1.There is only a handfull of tuners that can actually do the tune on it.I've done several 5.7 vortec conversions[5.7 uses that same pcm] fat chips tuned it,and it worked pretty well