I'm finally getting around to starting the engine build for my '81 resto mod. One of the key components I want to do is an EFI system in place of the old carburetor set up. Of course, it originally came with the Rochester electronic hoodanger that was pretty much garbage when it was new. I long ago tossed that into the bin and slapped on an Edelbrock 4bbl, which worked reasonably well. But I want the reliability and tunability of modern EFI. I have been considering the Edelbrock Pro Flo EFI system, but I always keep my eyes open for deals.

To that end, while perusing Craigslist a couple days ago, I stumbled across THIS ad. The owner tells me this a non-emissions GM EFI system originally designed for "off road" applications. Since I don't live in a location that requires emissions testing, not having all that stuff doesn't hurt me. I may still run cats on the car anyway just because.

But for those of you who have gone down this path before, any input on this system? Certainly looks like I'll need a few things, throttle body and controller at minimum, and certainly other small stuff. Maybe some other big stuff? But anyway, do you think I could get this set up to work equally well to the Pro Flo system for less than the new cost? Plus, as much as I like Edelbrock stuff, I'm leery of being married to a particular parts manufacturer.

For reference, the base engine this will go on is a factory 4 bolt, one piece main roller block with an older set of AFR 160 heads. The car, of course, is an '81 with a Richmond 5, so I actually don't want to get too stupid with power. I'll do some chassis tuning but without going full roll cage, those original frames were designed all the way back in the '50s.

 

That is a LT1 intake meant for 93 to 97 engines that has been modified to work on earlier engines. Notice the 2 AN fittings on the front of the intake meant for coolant. Does it include the remote T stat housing? The distributor was "added" to the intake. Was the proper angled washer used?

For the price I would pass. For me, it would have to be $100 or less to be worth the hassle. Then there might be a issue with hood clearance......

 

The GM TPI system used on the L98 engines in the 1980's was a basic efi system. It works okay on the L98 with the long runners but doesn't make a ton of power. My 1988 C4 is rated at 255 Hp. If I were interested in finding a good aftermarket EFI system I would go with a Holley EFI system that is pre-engineered and will work well on your application.

I have a Holley Stealth Sniper which is a basic Sniper EFI system with the throttle body turned 90*. It looks just like a carburetor but is a complete EFI system with incredible versatility due to the Holley EFI Software. I bought my entire system from a company who provides 24 months of POST-Sale service. The 2 years of support should be enough time to get your EFI system running like a champ.

The company is called efisystempro.com and is located in Florida. They sold me my entire system for several hundred dollars Below my budgeted amount. If you contact them they can design a system just for you using the Holley components. Their tech support is some of the best in the EFI world and they are very nice to deal with.

 

OK, so from the ad and the discussion I've had with the seller, this is actually a GM product sold for "off road" vehicles as it doesn't have emissions equipment. He did say it comes with a separate thermostat but I don't know the deal with the distributor. I'm going to be down there tomorrow anyway so I'll take a look at it and find out who did the modification. Who knows? If it's a GM aftermarket part, there might have been a boss in the manifold for proper alignment. Guess I'll find out tomorrow.

As far as the Holley, I would consider their products, but I'm leaning more towards the Edelbrock. I like the fact that Vic still has a foundry here in the states (at least he did last I checked), and I'm not looking to hide the fact that it's EFI.

 

I recently added a FiTech throttle body FI to my 69. No issues. Runs great.

My recipe for trouble free (YMMV):

• Run ECU power and ground directly to battery
• Add ground strap to TB base.
• Block heat passages in intake/head
• If intake not open plenum design then make it one or add spacer.
• Make sure throttle cable not perfectly tight, leave slight slack.
• If possible air cleaner should have at least 3" of height, no hats or less than 3" filter (I violate that one as I had to use a drop base with a 2 5/8" air cleaner to fit with my spacer).
• Revisit tune and adjust big autotune swings until stabilized to within the range of autotune.
• if fuel pump frame mounted do everything you can to keep it cool, including running no less than 3/4 tank if necessary.

 

I run a FiTech throttle body as well. Have for a number of years now.
I'll add this.
Absolutely none drop to my airfilter.

 

Looked at it. Took a pass. Just too much modification already done. Not convinced of the quality.

 

IronJen
I converted the RamJet 350 MEFI system to use the EZ-EFI 2.0 retrofit system for GM TPI. Pretty much plug and play after I used my MSD distributor.
IF that 93-97 modified/converted LT1 system is well done, then it would be an easy mod and you'd have port fuel injection.

 

A sniper system is a very basic system the wb O2 makes it advance but its still a TBI. TPI is great for TQ you can still run a Holley but it will be MPFI far superior to TBI. Also if you run a cam / crank sensor you run sequential. You can run large runners on a TPI with a good cam and make good power to about 4500 which is perfect for the street. They can be had for pennies now a days.

 

Before you start categorizing the various options maybe you ought to read about the Holley EFI software's abilities. The throttle body may be a simpler way to fuel inject an engine but it is not a simple device. The EFI software allows you to customize everything to your engine's liking. It is a nice piece of software and you can download it and play with it.

I chose the Holley Stealth Sniper because of the way it sits on the engine, it has nothing to do with hiding the fact that I have EFI on my 427. The Holley Sniper series has been replaced by an updated version and even so I am very happy with the first generation of Sniper.

When comparing the options available I chose the Holley over the FiTech and Edelbrock systems because of the way the system was designed. I chose the place I bought my system from because they would virtually guaranty the success of my installation. If and when I upgrade my system it will clearly be built with Holley components and controls.

 

Question? I read somewhere that when converting to EFI you need to run a larger diameter fuel line from the tank? Yes? What size? Sorry for thread-jacking. I have a 95 LT1 sitting in the engine bay of my 75 and need to start plumbing lines and stuff. Thanks!

 

vwcorvette
I am running with RamJet 350 (supposedly 350 HP & 400 lb-ft) using a 3/8" fuel line. Don't think you'd need anymore for TPI or the 95 LT1..

 

No problem. It's a good question. I need to know too.