1991 Suburban 3/4 ton: TBI to Holley Sniper conversion - stupid, or worth it?

[GTP51]

Having put a Sniper on my truck, I can offer the following observations, putting a sniper on an old tired 350 is a waste of time and money you will not get any benefit from it , in fact you will more than likely find it’s a regressive move. My 350 is worked 10.5 comp heads Comp cams cam biggest they recommend for a vortex and all worked internals, Edelbrock manifold and good pipes, it gets up and goes and is real nice to drive now, BUT it’s not plug and play with a sniper and don’t let anyone tell you it is ,if you want it to run right.
There is a place that modifies TBI units porting and smoothing etc, I bought one before going heads and cam and sniper etc etc and it made the stock truck much nicer to drive. I still have that unit here in a box on the shelf .
Unless you are prepared to spend some serious bucks on that 350 stay away from the sniper it’s only going to burn you and Holly are Ar..holes on warranty

 

[Fight Milk]

Did you end up making the swap?

I've thought about this, too. Eventually, I'd like to get a 5.3 or 6.0 and a 4L80E to put in my Suburban, but that's going to be a longer project. I'm leaning towards just using that money for the swap.

 

[edgephoto]

You can still buy parts for the GM TBI including reman units. I have owned my 1987 V3500 with 7.4L since 1988. Never had issues with it running, starting or drivability. The engine has never been apart except to replace gaskets.

I believe Holley is on a second generation of their Sniper system and the "support" for the first Generation is to sell you an upgrade to Gen 2. This is second hand from a trusted friend who tried the Sniper on his heavily modified Sniper. He said he took it off because he got tired of riding home on a flat bed.

 

[chief_shotts]

Heres my two cents:

When i bought the holley sniper Intended to use it with a built 383 stroker that i planned to put in my truck. But because i was impatient I immediately threw it on the old TBI 454 i had in my truck. I also swapped on a no name single plane intake manifold I had on the shelf and put long tube headers on with an exhaust held on with clamps and chicken wire. The results: Loud and Fast. Those bolt on items woke the 454 right up and made it a blast to drive. This is not speculation about what might happen... this is what did happen. Since then ive put a fresh 383 stroker with a retrofit roller cam in the truck and still using the sniper tbi. My only advice if you do use any aftermarket injection system... have it proffesionaly tuned by a real professional and not joe shmo at the local dyno.

 

[Strick]

I've bought my (wife's) 80Z28 back a couple years ago. It has been "updated" with a Sniper since my building it 15 years ago & I'm very disappointed with it. There's a puny 20 gauge wire for the HEI & it has killed two distributors already.
After buying this car back & running (initially) with the Sniper, I was satisfied. But after the HEI issues I've discovered a serious flaw in the system.

HS

 

[Ricko1966]

I've bought my (wife's) 80Z28 back a couple years ago. It has been "updated" with a Sniper since my building it 15 years ago & I'm very disappointed with it. There's a puny 20 gauge wire for the HEI & it has killed two distributors already.
After buying this car back & running (initially) with the Sniper, I was satisfied. But after the HEI issues I've discovered a serious flaw in the system.

HS

You are supposed to use that wire as a trigger for a relay so you can run a heavy gauge wire for power from the battery or starter post. I can tell you how to wire that circuit. Get a typical 4 prong relay run terminal 30 to your power source. Run terminal 87 to your distributor. Run terminal 86 to ground. Run that 20 gauge signal wire to terminal 85.

 

[Strick]

You are supposed to use that wire as a trigger for a relay so you can run a heavy gauge wire for power from the battery or starter post. I can tell you how to wire that circuit. Get a typical 4 prong relay run terminal 30 to your power source. Run terminal 87 to your distributor. Run terminal 86 to ground. Run that 20 gauge signal wire to terminal 85.

I may do that when I get a few hours to devote to messing with it. Thanks for the info. I've been sorely disappointed with the Sniper on this car.
HS