383 TBI vs 454 TBI, need opinions

[77 K20]

http://paceperformance.com/attachment/34550-.pdf

This was why I went with GM's HT383. Peak torque at 3,300 RPM. With my gears I'm running that RPM at highway speeds. Even at only 1,500 RPM it makes 380 ft/lbs.

And it does it with a little baby cam that makes great vacuum at idle. (21")

 

[gmachinz]

Have you thought about looking for a GM 496 8.1L BB? Gobbs of power and not as hard to find as you'd think. Usually found only in workhorse trucks so finding one that doesn't need an overhaul could be tuff.

 

[77 K20]

I have the 8.1 in my 2003 Silverado HD. They were also in some of the Chevy Avalanches. But rumored to be de-tuned a bit since they were only mated to the 4l80e. (instead of the allison or ZF-6)

 

[gmachinz]

There's an older you-tube video of a Cutlass wagon with an 8.1 and a Doug Nash 5-speed doing crazy burnouts....I love that video-I'll see if I can find it....

 

[gmachinz]

http://bangshift.com/general-news/v...-of-vortec-big-block-and-a-doug-nash-5-speed/

Sorry it was bangshift.com awesome video!

 

[Daveo91Burb]

http://bangshift.com/general-news/v...-of-vortec-big-block-and-a-doug-nash-5-speed/

Sorry it was bangshift.com awesome video!

Cool! We had one of those when I was a kid, it was dark red and a '78 I think, but pretty much the same. Didn't have an 8.1 in it, though, I can say that for sure. I think it was one of those economy V-8s they had back then, smaller than a 305. 267 maybe? I've actually thought about buying one to build up (LS 5.3 maybe??) but they are getting really hard to find. Especially the Oldsmobile version which is what I would want.

Anyway, guys I would love to do a vortec 454 or 8.1 for the Burb, but I think it may be a bit out of my league. Mainly regarding fuel supply - I think budget, time and skills restraints would prohibit me from figuring out a way to fuel inject it. And I don't want to go backwards to a carb since it's a '91 and has a 4L80e. One thing I've been wondering and have not really been able to figure out from internet research - can you even buy a 4-barrel intake manifold for a Vortec 7.4 or 8.1? Just curious, though...

Nah, I'm going to stick with the Vortec 383, and run the TBI. The fuel injection guy I've been talking with insists he can make this work, I just have to use 454 injectors. (I think he's telling me to get 84 lbs/hr ones). I'm starting to get excited about the build - a commitment I have during the winter is ending in a few weeks and I've gotten the go ahead from the boss at home.

 

[4WDKC]

Cool! We had one of those when I was a kid, it was dark red and a '78 I think, but pretty much the same. Didn't have an 8.1 in it, though, I can say that for sure. I think it was one of those economy V-8s they had back then, smaller than a 305. 267 maybe? I've actually thought about buying one to build up (LS 5.3 maybe??) but they are getting really hard to find. Especially the Oldsmobile version which is what I would want.

Anyway, guys I would love to do a vortec 454 or 8.1 for the Burb, but I think it may be a bit out of my league. Mainly regarding fuel supply - I think budget, time and skills restraints would prohibit me from figuring out a way to fuel inject it. And I don't want to go backwards to a carb since it's a '91 and has a 4L80e. One thing I've been wondering and have not really been able to figure out from internet research - can you even buy a 4-barrel intake manifold for a Vortec 7.4 or 8.1? Just curious, though...

Nah, I'm going to stick with the Vortec 383, and run the TBI. The fuel injection guy I've been talking with insists he can make this work, I just have to use 454 injectors. (I think he's telling me to get 84 lbs/hr ones). I'm starting to get excited about the build - a commitment I have during the winter is ending in a few weeks and I've gotten the go ahead from the boss at home.

get the whole 454 vortec truck, pull the harness out and get a 0411 ecm from a 00-02 van. Your factory fuel system just needs a better pump to support the vortec 454.

working on doing the vortec head swap to my V10 also, lots of info out there if you have the desire to tune it yourself.

 

[Daveo91Burb]

Good to know, thanks. I think buying an entire vortec truck will exceed the budget but never know.....may run across one for cheap some day


Sent from my iPhone using Tapatalk