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Discussion Starter #1
Hey guys I'm back with anew question. I had a 327 i wanted to drop into my truck but decided not to do it. I was wondering if i could drop in a 400 instead of the 327. Can I hook up the tbi and run the 400. Will I need a new chip? I saw in the JEGS they sell a JET Performance Stage 2 chip for a 88 truck. Will this run it? I plan on running vortech heads and vortech tbi manifold with K/B pistons. Also what kind of cam could I use in this setup? The truck is a daily driver and I don't plan on racing it or tow anything.
 

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You're going to have to get a custom chip burned for it or get the equipment to burn chips yourself. The later is often the most cost effective optionion. This due to the fact that often you'll have to burn several chips before you get it right.
You could get an adjustable fuel pressure regulator and try increasing the fuel pressure until it runs right but I think that jumping up to a 400 motor would be a little out of the window for poor boying it.
 

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Did you have a 350 or 305 in your truck?

In either case, I'm sure the truck would RUN, but the injectors over a 305 aren't going to put out enough gas as the engine gets up in rpm's. The injectors for a 350 are usually a little higher flow, but you will likely still start to lean it when it gets revved way up. Either system is supposed to be 480 cfm, but the larger engine will generate a little bit more vacuum, and thus suck in a little bit more air.
I've heard of people slapping their 305 intakes on 350's, but the injectors usually max out their flow rate.

This can be overcome by getting flow-matched injectors. 305 injectors are supposed to flow 40 lb/hr, 350's are supposed to flow 55 lb/hr.

If you want higher performance, I'd check into finding ones for a police package, which are supposed to flow 65 lb/hr.

I've heard that GM allowed 5 lbs either way on most injectors, meaning you could have 2 that flow 35 at the lowest, which would really be too little fuel to keep a 400 happy.

Chris
 

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Burn Your Own Chip? - Other Ideas

tresi said:
You're going to have to get a custom chip burned for it or get the equipment to burn chips yourself. The later is often the most cost effective optionion. This due to the fact that often you'll have to burn several chips before you get it right.
You could get an adjustable fuel pressure regulator and try increasing the fuel pressure until it runs right but I think that jumping up to a 400 motor would be a little out of the window for poor boying it.
Burn your own chip, that sounds like an awesome idea. Who is a source for this?

How about running a 454 TBI unit with or without a fuel pressure increase. This of course would still require a custom chip, not an off-the-shelf piece like the ones at Jegs.

I would run the stock Vortec cam in a 400 in a truck application.

A couple of good TBI sources are:

1. Howell Engine Development

2. CFM-Tech

Good luck with your project, Ed www.edgesz28.com
 

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Discussion Starter #5
My truck has a 350 in it now. How would I go out burnig my own chip? I also planned on using a 454 tbi unit or would Holleys tbi work. The vortec cam would be out of a vortec 350 right?
 

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If I`m not mistaken the injectors are color coded to the size of the engine...? I know that the part numbers for a 305 & 350 are different and that they dont interchange other than in appearance...? Also the 454 unit is larger and will not fit a SBC TBI intake... It will bolt on but not open (butterflies are larger)... Also the 454 injectors put way to much fuel for even a 400 to handle...

But...! the alternative is possibly find a fuel injected (TBI) truck with a 366 BBC in it but use the 350 fuel pump... The fuel pump for a BBC either the 366, 427, 454 (yes their are some TBI 427`s in big trucks like Kodiac`s) are higher volume pumps as opposed to the ones used on a 350, 305, 262 (4.3 V6)... So possibly with the larger injectors (from the 366 unit) and an adjustable regulator and the stock 350 pump you might be able to tailor it in...?
 

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Discussion Starter #7 (Edited)
So Bumpstick where would I find these injectors? From a hvy duty truck supply store? What about the JET adjustable regulator?

So Bumpstick where would I find these injectors? From a hvy duty truck supply store? What about the JET adjustable regulator?
 

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With TBI, you really don't have to worry much about too much fuel, becuase the computer can always give the truck LESS fuel, but the only worry is getting enough fuel, because the injectors will max out at a certain amount. Also, I would guess that the 400 will probably be revving up higher than the 454 would.

You can take the injectors from the 454 and put them in the original TBI, so it will just be like a beefed up 350 injector. I'm not sure about 454 TBI's larger diameter throttles not working, as I often hear of TBI's for 305/350 with larger bores and butterflies, but maybe the 454 is even bigger.

I suppose you could take a grinder and open up the bores on the intake a little. Would probably be worth it for a little more air flow.

Chris
 

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pete379 said:
The vortec cam would be out of a vortec 350 right?
Yes.

Please check these guys out : http://www.cfm-tech.com/catalog/ Scroll down and click on the "GM Tbi Performance Parts + Accessories" I can't seem to get the full link to work :confused:

Instead of getting the high dollar TBI Vortec manifold, perhaps you could consider a dual plane Vortec 4-barrell intake and use this adapter. . The adapter should easily accomodate the bigger 454 throttle blades. That way, if you ever wanted to go to carb, the intake is already there. Plus, I did not check parts and pricing, but the combination of a 4-b intake and adapter may save you a few coins over a TBI Vortec intake.

Good luck, Ed www.edgesz28.com
 

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www.moates.net

Here's the link to Moates site where you can get all the hardware and info needed to burn your own chips. It will take some studying on your part but it's do able at home.
 
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