[ZeGermanHam]

A trap door would add convenience, but is it worth cutting a big hole in your car for the relatively infrequent need to service the pump? I don't find dropping the tank in an A-body to be particularly difficult or time-consuming.

[NeighborsComplaint]

Yeah, I though about that too. On mine I have to drop the exhaust. I saw this 10"x14" waterproof hatch, but I'm not sure I want to cut up my new trunk floor ... it sits 3/4" high so I would install it over the trunk mat and the cut neatly around the flange, hsind the mat as a gasket.

[ZeGermanHam]

Originally Posted by NeighborsComplaint

Yeah, I though about that too. On mine I have to drop the exhaust.

Ah, gotcha.

[Scarebird]

How is this exhaust routed?

[NeighborsComplaint]

They exit through the rear valance panel. The flanges of the tank won't clear the tailpipes and the tank doesn't drop far enough to angle it out. The tailpipes have to be dropped down onto the rear axle housing for the tank to come out but because my system is fully welded, I have lower the entire system in one piece. I have to disconnect at the collectors, remove the mid-pipe and tailpipe hangers and lower the whole system, supporting the front while the tailpipes rest on the rear axle.

[NeighborsComplaint]

'If you look at the '71 from the side, you don't see the tailpipes like you do on earlier models that exit below the bumper. They are tucked up into the quarters.

[RocktimusPryme]

Originally Posted by ZeGermanHam

A trap door would add convenience, but is it worth cutting a big hole in your car for the relatively infrequent need to service the pump? I don't find dropping the tank in an A-body to be particularly difficult or time-consuming.

Personal preference for sure. My trunk is already an aftermarket replacement and has tech screws from underneath holding in line clamps. So it wouldnt bother me at all.

I wouldnt call dropping the tank hard per say, but I still dislike doing it. You either have to drain it or deal with liquid sloshing about. I just dont like extra work. Having to drop the tank simply to be able to screw on an AN fitting? That bothers me. Which is my own personal mental block to be sure.

[67Fbird]

A method i utilize is a simple scab plate. Basically 1/8 pice of alum to make a picture frame (about 1" wide). Beat the aluminum to your floor shape then what you cut out goes right back in with a 1/2 "lip" inside the hole 1/2" lip to the floor. Then seal/ blind rivet the "frame" to the underside of the floor. Drill and tap, countersink a few holes...perfcetly flush and formed per it USED to be the floor!

Nice addition...but some cars it is very easy to access the fuel tank so...50/50. My 2nd gen F-body tank drop absolutely sux.

[Formulajones]

Tanks Inc sells a nice stainless trap door that I've used on several installs. It sits very flat to the floor, and once the trunk mat is over it, you can't see or even detect it.

I recommend the trap door for a lot of reasons. A big one is if you really enjoy driving your car long distances. The pumps rarely fail but if they do, it's usually at the most inconvenient time, like with a full tank of gas, or while you're out on the road somewhere.

I was doing an install and had a wiring issue. The clip at the pump pushed the wires out as the clip was snapped in. Didn't notice it. Had it all wrapped up with gas in the tank ready to purge the lines for trash before hooking it to the engine and the pump wouldn't run. Nice thing about the trap door is having that pump back out in 2 minutes, with gas in the tank, never spilling a drop. Found the issue and fixed it. Literally done in 5 minutes and I didn't even have to get under the car. That trap door paid for itself before I even had the car running, lol.

Keeping a spare pump in the car for a planned road trip, can literally be swapped in on the road side with a trap door if there were ever an issue, and could be done in 15-20 minutes. That's the big reason I do the trap doors.

Otherwise I wouldn't care if every time I needed at the pump I was at home on the lift with the transmission jack under the tank. I can drop it down in 15 minutes. But when am I ever conveniently at home with proper equipment when something happens.

It's kind of like having those particular speed parts on the car that you can only buy from a speed shop or online. When do any of those ever fail and leave you stuck right outside Summit Racing?? LOL

[djustice]

Dropping the tank Sucks big time, i have dropped mine 2 times since i Converted to efi, 1 time to modify the tank for a proper return-line.
2.nd time to throw the whole tank in my "shed" and buy an efi tank lol.
Now with all new efi tank i am on the werge of pulling it a 3.rd time! because of sender issues.
After a LOT of trial and error and even a brand new programmable fuel gauge from speedhut i found that the new sending unit that came with the efi tank has a partially defective rehostat.
If i fill the tank to the brim the gauge will show empty with an occational flash of the needle moving. If the car is going downhill it wil mostly show 0 when going uphill the gauge works fine.
and it works fine when i get to about 1/2 tank all the way down to 0. and i am not pulling this tank again :/

[Scarebird]

Originally Posted by NeighborsComplaint

They exit through the rear valance panel. The flanges of the tank won't clear the tailpipes and the tank doesn't drop far enough to angle it out. The tailpipes have to be dropped down onto the rear axle housing for the tank to come out but because my system is fully welded, I have lower the entire system in one piece. I have to disconnect at the collectors, remove the mid-pipe and tailpipe hangers and lower the whole system, supporting the front while the tailpipes rest on the rear axle.

Ah. If you do not wish to go the trap door route, you may want to cut the tail pipes on that somewhat vertical straight section just aft of the axle and use a band clamp to secure.

At minimum it will show that tank you are not fooling around.

[NeighborsComplaint]

That and I can give the pump the "If you don't perform you can be replaced" talk.

The "boat hatch" is not for me. I just threw it out there. A GM metal body plug measures 4-5/8" x 3-11/16". I don't know if that is large enough or if enough clearance exists to rock the pump/sending unit assembly out through that opening even leaving a minimal flange to screw or seam seal it to. I'll measure the flange on the tank when it arrives but I'm guessing it's not going to work but I can always mock it up with cardboard and see.

[NeighborsComplaint]

Originally Posted by NeighborsComplaint

That and I can give the pump the "If you don't perform you can be replaced" talk.

The "boat hatch" is not for me. I just threw it out there. A GM metal body plug measures 4-5/8" x 3-11/16". I don't know if that is large enough or if enough clearance exists to rock the pump/sending unit assembly out through that opening even leaving a minimal flange to screw or seam seal it to. I'll measure the flange on the tank when it arrives but I'm guessing it's not going to work but I can always mock it up with cardboard and see.

Not to mention limited access to the flange mounting bolts.

[Formulajones]

You really need the 8 1/2" wide by 4 3/4" deep trap door from Tanks Inc. That way you can access both the pump and the sending unit at any time. I find that's just the perfect size to get both pieces in and out with just enough wiggle room.

It's really no big deal. The first time you have to use it you'll forget all about the anxiety about cutting the floor. With your situation it really sounds like you need it anyway with a tank that won't drop without removing the exhaust, and an exhaust that doesn't disassemble easily kind of backs you into a corner.

Hell I traveled the country to buy our rust free cars that I've owned for 30+ years and I didn't give cutting a small square hole in the trunk a second thought, and a few of the cars today aren't cheap to buy or easily replaced. It can easily be welded back in, a little body work and I can make it appear as if it was never there in the first place.

[389]

With the amount of money you will have in this after its all ironed out and running halfway decent you could of bought an exotic intake like the Man-A-Fre. They have them all ironed out today and they run hard..

[NeighborsComplaint]

While I am waiting on my fuel tank, a new open box Sniper Dual Synch Distributor just popped up on my "radar" for 2/3 the going price. I'd have to buy the adaptor harness and an external coil on top of that of course and would be using my old MSD Box.

Do you think this worth the other and expense over my HEI? In all likelihood I would put in my current timing curve and leave it alone. No laptop tuning or tweaking beyond that so wondering if it's worth the bother.

[Formulajones]

Just my opinion because I'm always trying to wring what I can out of the cars but with no laptop tuning you really aren't reaping all the benefits that both the electronic control of fuel and timing have to offer.

But even with that said it's still worth while to have timing control. You can tweak things with the handheld and there are some benefits that come with that.

[NeighborsComplaint]

Originally Posted by Formulajones

Just my opinion because I'm always trying to wring what I can out of the cars but with no laptop tuning you really aren't reaping all the benefits that both the electronic control of fuel and timing have to offer.

But even with that said it's still worth while to have timing control. You can tweak things with the handheld and there are some benefits that come with that.

Yeah. Digital vs vacuum/mechanical advance and ability to easily tailor the timing curve would be a advantageous. I could go New Hyperspark or Open Box Dual Sync for the same price.

[NeighborsComplaint]

Just noticed the dual sync come with a hardened steel gear. That would not work with my HFT cam gear. I would have to change the distributor gear and the only optional gear is a bronze one from Holley. I' sure it would be fine but I'd be more comfortable with cast iron like on the Hyperspark unit.

[Formulajones]

Well isn't that interesting. I never paid attention to that. I'm guessing they are all .500 shafts then.