Holley Sniper and Gas Tank Swap

[chuckler3]

Aside from the fun of doing this during a Florida summer under a carport, yes. Gave me an excuse to pull my cheap welder out for the first time in a decade.
The less fun part is coming though. I hate wiring. Add to that, this thing has been gone through a number of times by different hands and the wiring is far from stock.. There's gonna be some head scratching soon.

 

[consti2tion]

I've got all my pieces and parts together to put a Sniper and the hyperspark on my Suburban, will be tackling it this weekend. I bought an EFI tank and am using the factory sending unit with an AEM fuel pump, using the stainless braided PTFE fuel lines where any flex hose would be.

 

[chuckler3]

I've got all my pieces and parts together to put a Sniper and the hyperspark on my Suburban, will be tackling it this weekend. I bought an EFI tank and am using the factory sending unit with an AEM fuel pump, using the stainless braided PTFE fuel lines where any flex hose would be.

Nice. I'll probably kick myself later for not just doing the hyperspark now. I'm kicking myself now for not getting the blueprint block prepped for fuel injection and just doing this whole thing when I did the motor swap. Hindsight...

I can conceive of doing the project in a weekend, but I'm enjoying a relaxing pace considering I'll have about 3 months in the project by completion.

Just figured out the wiring for the fuel pump and sorted that out. Still have wiring for the distributor and actually strapping down the fuel lines, and bleeding all the new brake lines... that's a consideration for tomorrow now though. Should have it running by the end of the month.

 

[SquareRoot]

Somebody say the "S" word?

 

[consti2tion]

Nice. I'll probably kick myself later for not just doing the hyperspark now. I'm kicking myself now for not getting the blueprint block prepped for fuel injection and just doing this whole thing when I did the motor swap. Hindsight...

I can conceive of doing the project in a weekend, but I'm enjoying a relaxing pace considering I'll have about 3 months in the project by completion.

Just figured out the wiring for the fuel pump and sorted that out. Still have wiring for the distributor and actually strapping down the fuel lines, and bleeding all the new brake lines... that's a consideration for tomorrow now though. Should have it running by the end of the month.

I am taking my time doing this as well. Making sure I like where I am routing all wiring related to the Sniper and Hyperspark. It's tedious trying to do it right but I don't want it to be a mess to fool with in the future.

I should have replaced the intake manifold while I was at it but I can't justify it on a stock 80's big block.

 

[chuckler3]

I am taking my time doing this as well. Making sure I like where I am routing all wiring related to the Sniper and Hyperspark. It's tedious trying to do it right but I don't want it to be a mess to fool with in the future.

I should have replaced the intake manifold while I was at it but I can't justify it on a stock 80's big block.

Yup.. just came to the realization yesterday that I need a relay to run the sniper.. So now I'm waiting on that and some fatter wire to come in.. only had 18g..
Also need a new rear-diff cover.. figured since I had the new tank out of the way to paint and run rubber I'd do the rear gear oil.. Minimal unicorn dust in there at least.. Old cover had a dent internally sticking out so someone had the rear out of it in the last 4 decades.. Waiting for that to come now too..
All wiring is done aside from the Tach tie-in, and 12v switched power from aforementioned relay.

Need a brake bleed, fuel system prime, and some gear oil, then I can finally fix the leaky trans pan.. Maybe I'll get to drive this thing before October. Then big decisions for the bed.. Keep it and really work through routing the new fill tube to the stock fill location on the side.. Really want that. Not sure how realistic that will be until I get the bed up on some wood..

 

[77 K20]

Also need a new rear-diff cover.. figured since I had the new tank out of the way to paint and run rubber I'd do the rear gear oil.. Minimal unicorn dust in there at least.. Old cover had a dent internally sticking out so someone had the rear out of it in the last 4 decades.. Waiting for that to come now too..

Wow- so even with a 4" lift you think the rear differential will hit the fuel tank?

I haven't heard this was a possibility. And what would happen if there was a 14 bolt back there... even worse then, right?

 

[chuckler3]

Wow- so even with a 4" lift you think the rear differential will hit the fuel tank?

I haven't heard this was a possibility. And what would happen if there was a 14 bolt back there... even worse then, right?

I went with the 32 gallon and didn't make any modifications to the existing hitch mount or rear crossmember. Moving/removing the rear crossmember and/or shifting back the hitch mount would alleviate any issue. I'm not even sure the contact is an issue to worry about. The axle should travel forward a bit while compressing. Regardless, it's close enough for my dumb brain to look at it and consider it a possible issue. I've had over 1000lbs in the bed and only had the rear suspension compress 2", 3" over bumps.

I need to get longer bump stops anyways. Gotta find those at some point.

 

[77 K20]

Axles travel rearward when compressing. The leaf spring is attached at a fixed point at the front side of the leaf. Can't move forward. As the leaf flattens out it grows "longer". The shackle moves rearward and the axle shifts to the rear a bit in response.
But I get what you are saying now about making room for your hitch/crossmember.

 

[consti2tion]

Yup.. just came to the realization yesterday that I need a relay to run the sniper.. So now I'm waiting on that and some fatter wire to come in.. only had 18g..
Also need a new rear-diff cover.. figured since I had the new tank out of the way to paint and run rubber I'd do the rear gear oil.. Minimal unicorn dust in there at least.. Old cover had a dent internally sticking out so someone had the rear out of it in the last 4 decades.. Waiting for that to come now too..
All wiring is done aside from the Tach tie-in, and 12v switched power from aforementioned relay.

Need a brake bleed, fuel system prime, and some gear oil, then I can finally fix the leaky trans pan.. Maybe I'll get to drive this thing before October. Then big decisions for the bed.. Keep it and really work through routing the new fill tube to the stock fill location on the side.. Really want that. Not sure how realistic that will be until I get the bed up on some wood..

Yes you definitely need a relay, not sure why they don't just include that along with the fuel pump relay. I dropped the tank on the suburban yesterday, need to get new filler neck rubber hose and get the lines sorted.

I decided to run a Corvette fuel filter/regulator. Are you running a return line back to the tank from the Sniper or going with the inline filter/regulator?

 

[chuckler3]

Yes you definitely need a relay, not sure why they don't just include that along with the fuel pump relay. I dropped the tank on the suburban yesterday, need to get new filler neck rubber hose and get the lines sorted.

I decided to run a Corvette fuel filter/regulator. Are you running a return line back to the tank from the Sniper or going with the inline filter/regulator?

Yes. Send and return lines for fuel. I unfortunately will need to use a couple of zip ties in addition to the appropriate, insulated fuel line clamps due to limited access around the shock mount area of the inner frame near the headers. I'll survive though.

Finished up all but the relay-to-sniper wiring yesterday. Have an inline fuse to add between those two... Hard to use a heat gun on an extension cord in a thunderstorm (under a carport). Otherwise.. it's just waiting on the 2 plug adapter to mate with the Holley in-tank fuel pump (88 blazer) and a whole mess of wire loom to tidy things up in the bay. And of course all the liquids that need to get swapped out.

Starting my research on filler hose and how I can route it to get to the stock filler location. So far, it's not looking good. Tank is oriented to injest from the driver's side but being mounted behind the rear axle means a decent run that's going to interfere with the wheel well. Let the headache begin.

 

[chuckler3]

Axles travel rearward when compressing. The leaf spring is attached at a fixed point at the front side of the leaf. Can't move forward. As the leaf flattens out it grows "longer". The shackle moves rearward and the axle shifts to the rear a bit in response.
But I get what you are saying now about making room for your hitch/crossmember.

That'll make the bump stop search all the more interesting.

 

[consti2tion]

Yes. Send and return lines for fuel. I unfortunately will need to use a couple of zip ties in addition to the appropriate, insulated fuel line clamps due to limited access around the shock mount area of the inner frame near the headers. I'll survive though.

Finished up all but the relay-to-sniper wiring yesterday. Have an inline fuse to add between those two... Hard to use a heat gun on an extension cord in a thunderstorm (under a carport). Otherwise.. it's just waiting on the 2 plug adapter to mate with the Holley in-tank fuel pump (88 blazer) and a whole mess of wire loom to tidy things up in the bay. And of course all the liquids that need to get swapped out.

Starting my research on filler hose and how I can route it to get to the stock filler location. So far, it's not looking good. Tank is oriented to injest from the driver's side but being mounted behind the rear axle means a decent run that's going to interfere with the wheel well. Let the headache begin.

I spent a lot of time trying to get the wire looms to look clean under the hood, a lot of moving components around etc. The hyperspark added a some more frustration on the wire routing and placement though so it shouldn't be as bad for you.

I considered just buying the fuel lines from "linestogo.com" for the FI suburban but decided to just go another route.

Fuel filler hose is surprisingly expensive at local autoparts stores but not too bad on amazon. I need to figure out a better system for routing mine on a completely different project and it is hard to figure out what will actually flow correctly and vent properly when filling so it won't "burp" or click the pump off constantly, I think that will be the most difficult task. I have a 1971 Dodge Sweptline with a D250 chassis swap and currently I just have the fuel filler in the wheel well, if you aren't able to get it routed easily you could poke it out in the wheel well and build some sort of cover/door over it.

 

[Vbb199]

Somebody say the "S" word?

While the community appreciates and loves all opinions, respectfully, your failed holley installation doesn't make ALL holley efi junk.


-signed the entire high performance community that makes more than the 450hp the PF4 supports

 

[Bextreme04]

Yes you definitely need a relay, not sure why they don't just include that along with the fuel pump relay. I dropped the tank on the suburban yesterday, need to get new filler neck rubber hose and get the lines sorted.

I decided to run a Corvette fuel filter/regulator. Are you running a return line back to the tank from the Sniper or going with the inline filter/regulator?

I thought the sniper had its own internal regulator....

I've heard mixed reviews on the integrated corvette filter/regulator. I ended up just going with an external adjustable regulator on the return line so that I could vacuum reference it to the manifold and maintain a consistent fuel flow. Makes it a bit easier to tune the EFI when you don't have good injector data.