So my daughter and I are building my late older brothers last toy he bought before his passing. I haven't even picked it up yet. I've seen it and know it needs alot of work. The engine is missing, I believe the trans is present but have no idea if any of the TPI components are present. It is my intention to get a decent running 96-2000 Vortec 5.7 (non LS based) to transplant. I know I have to use an aftermarket lower intake to bolt the TPI to the Vortec heads. Here are my questions:

Is the 91 C4 oil pan chassis specific?
Is a 4L60E swap reasonably easy in that chassis?
How programmable is the factory ecu? I.e. 4L60E funcrion, aftermarket injection.
Am I better off to run a standalone ecu with the Vortec injection rather than swapping everything out?

If memory serves me correctly, TPI runs a flashable PROM rather than a programmable PCM like the newer LS based packages.

You thoughts/knowledge/opinions are welcome and appreciated. ok

Dan

 

Yes. Truck pan might work, but it will hang down lower (get hit).

4L60E should be a bolt in (physically) if you have a C4 specific tail shaft housing on it.

The factory ECU has no capacity to manage the 4L60E, because the "E" was never offered when the TPI ECM was in use.

I haven't programmed the 91 so I can't comment, but I'd GUESS that it's similar to most other OBD I ECM's; once you have all the equipment it shouldn't be too bad.

The Vortec intake injection has plusses and minuses;
PLUS:
*The intake is a mid-length runner intake and as such it would support more HP and a higher RPM range. Heck, the STOCK vortec truck engine made more hp than the baddest L98 ever offered.

* Sequential EFI (FWIW)

Minus:
*Injectors limit max hp with the Vortec system

*Doesn't look as nice.

*Not sure it would fit under the 'Vette hood with the TB hat on there. (?)

 

That's really what I want the Vortec motor, the heads. Even in stock form the do pretty good and if I do a mild bowl blend and port match.....
So adding a 4 inch outlaw cowl hood to the parts list... JK.
I'm pretty sure it will fit under the hood. The TPI intake seemed pretty tall in comparison but I may be imagining on the optimistic side. Either way, I can fabricate a custom hat for it and shave an inch or two.
Thanks for the info on the pan, I better go ahead and get a C4 specific pan. So I'm geussing I would have to modify the torque link for the 4L60E install.
The stick injection should make plenty if torque/HP to keep her happy for awhile. Please read " on her own insurance and not mine"😆
Do you have any experience with any of the standalone controllers? I've used FAST a couple times but mostly programmed factory ECU's in LS based stuff. I have been looking at Megasquirt since they are inexpensive but don't don't really know anything about them. As an alternative I could run an FI Tech or EZ EFI (FAST) standalone TBI.
Really kinda up in the air on this thing.
Is it expensive to get the factory TPI stuff for these?
Back when TPI was popular I was much younger and still willing to put up with heavily cammed, high compression big blocks on the street. God I was a dumb kid! You ever drive a "street car" with a Jericho 5 speed that required C12 race fuel on a daily basis? Somebody should slapped some sense into me.....
LMAO
Thanks for the info, I'll probably have more questions along the way.

Dan

 

There isn't much that fits under the hood of these things. If you don't have the tpi manifold I wouldn't look too hard for it, it's a huge restriction over 4500 rpm. If you do buy one don't spend over $25-50, I tried to give mine away for the cost of shipping and there were no takers.

You are correct that the tpi has a prom that needs flashing. Shouldn't be too hard to find a local place to do it, if not I know there are places that will send you one mail order. Pcmforless or pcmofnc something like that, I can't remember exactly.

This forum is a good resource for parts and information, members are usually happy to help out. Good luck

 

Perhaps he can put a hood scoop and that will open up options?

IDK. You want the shop to be good and they don't see as much of the old stuff as they used to so they might have phased it out. I personally am not a fan of "guess a tune" but if they datalog and make changes, it probably would be better than you giving specs and they burn something they think might work. For that reason, I'd ask around first before I do anything so I know that within a year, they probably will do it and knock on doors after you get everything put together.