Gas tank and fuel pump question

[possum70]

I'm putting a 2003 5.3 into a 1978 K5. On the fuel pump issue I'm baffled, mainly because my tank isn't. Anyway, I have the standard 25 gal tank. What fuel pump is everyone using in tank and would it allow me to go to a 31 gal later? I know some pumps will expand a bit. Also, what do I need to do about the baffles? Do they come on the pumps? If not, can I use my tank now until I get a newer tank later? I won't be doing anything rough with it. Probably the most offroad will be on the beach.

possum

 

[dyeager535]

Depth of the tank governs the sending unit height, the pump has no bearing on that. With a fair bit of work I've seen some of the later combination fuel pump/sending unit/sump setups retrofit in earlier tanks, but unless there is a reason to do that, it seems like a lot of work for little reward, however that integral sump is probably more effective than the aftermarket tank baffles.

For on-road use, unless you do a lot of hard cornering, and like to run your tank low, you probably won't have a lot of issues without baffles. The aftermarket baffles are garbage anyway (better than nothing, but not by much), I wouldn't worry too much about it.

Really need to figure out how you are going to run your fuel system before purchasing things...using the factory Saginaw flares is going to be tough, but the Saginaw to -AN adapters are pricey too. If you are going to leave the 25 gallon tank in place indefinitely, then easy, buy a 25 gallon TBI sending unit (assuming they made them). If you have any thought of going 31 gallon now, buy everything for that tank. If nothing else, the extra time between fillups is nice.

 

[RootBreaker]

{subscribed}
want to see where you go from here...

i have dual 18g tanks as its a pickup but i want to drop a 8.1L in eventually and need to change out my pump...i figured on frame but someone said do tbi in tank pumps and can be done on dual tanks...

 

[Greg72]

I'm putting a 2003 5.3 into a 1978 K5. On the fuel pump issue I'm baffled, mainly because my tank isn't. Anyway, I have the standard 25 gal tank. What fuel pump is everyone using in tank and would it allow me to go to a 31 gal later? I know some pumps will expand a bit. Also, what do I need to do about the baffles? Do they come on the pumps? If not, can I use my tank now until I get a newer tank later? I won't be doing anything rough with it. Probably the most offroad will be on the beach.

possum

Two fuel tanks walk into a bar....

One fuel tank says to the other: "Say, what's your secret to keeping fuel from moving away from the fuel pump pickup?"

And the other tank looks at him with a confused look and says: "I'm baffled?"



-G

 

[RootBreaker]

Ok you get anywhere with this?

 

[possum70]

Well, I bought a 31 gal tank, ACDelco EP381, strainer (because it said it didn't come with one but it does), sender and new straps. I just got them yesterday but I have 2 running (should anyway) vehicles I need to get back on the road first; daily drivers.

 

[dyeager535]

Well, I bought a 31 gal tank, ACDelco EP381, strainer (because it said it didn't come with one but it does), sender and new straps. I just got them yesterday but I have 2 running (should anyway) vehicles I need to get back on the road first; daily drivers.

When you get a chance, can you check the tank internal sump/baffles? Curious if that has been improved.

 

[possum70]

I think this works. I'm uploading from my phone

 

[dyeager535]

Dang. Same worthless design as before. How does fuel get in at any level below the height of the sides of that sump/baffle? From the bottom. How does gravity work again?

Unless there is something I'm missing, like a one way check valve or something.

 

[possum70]

There are a couple holes in the bottom. I thought at first they were spot welds but they're holes.

 

[dyeager535]

There are a couple holes in the bottom. I thought at first they were spot welds but they're holes.

Yep. As far as I'm concerned that thing is for looks only. Might as well leave it out. It might provide a tiny bit of help with the right vehicle angle, but the OEM design works at any angle.

I'm sure it would make the tank substantially more expensive, but there really isn't any other reasonably priced option. This is why someone needs to make an adjustable depth sender that has an integral sump design for all GM vehicles that use the same tank sender mounting design.