Author Topic: 87 EFI Fuel Pumps into Dual Saddle Tanks??  (Read 20952 times)

Offline eisenhauer01

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87 EFI Fuel Pumps into Dual Saddle Tanks??
« on: November 15, 2009, 08:06:52 am »
Hello all, I am new to this forum but so far it has had a heep of helpful info on these trucks. This place is great!!  Just bought my truck and am very mechanically inclined.. ok, As it is, my 86 K10 SB 4x4 305 has dual saddle tanks. It has a mechanical fuel pump on the engine and a fuel selector switch in the cab that operates the fuel tank selecetion valve. My question:  I am planning on doing a 350 build for my truck and would like to switch to electric fuel pump(s)  (never been a fan of the mech. pumps) .. I was wondering if I should just install an inline pump between the selection switch and the engine, or if I should look into installing 87 EFI Sending units (pump/guage sender) into both of my dual saddle tanks. I dont want to go the blazer/burb tank switch because i want to run my dual exhaust straight out the back. Any help would be greatly appreciated.
1986 K10 Short Bed 4x4 305

Offline VileZambonie

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Re: 87 EFI Fuel Pumps into Dual Saddle Tanks??
« Reply #1 on: November 15, 2009, 08:49:53 am »
The dual in tank pump system is the way to go if you are going EFI
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74 GMC, 75 K5, 84 GMC, 85 K20, 86 k20, 79 K10

Offline eventhorizon66

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Re: 87 EFI Fuel Pumps into Dual Saddle Tanks??
« Reply #2 on: November 15, 2009, 11:59:18 am »
He didn't say he was switching to EFI.  It seems he just wants to eliminate the mechanical pump.

You'll definintely need a dynamic regulator like this one: http://www.summitracing.com/parts/MAA-4309/.  And an adequately sized return line.

Why do you want to make the switch?
'85 C10 SWB 350 700R4 TKO600

Offline VileZambonie

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Re: 87 EFI Fuel Pumps into Dual Saddle Tanks??
« Reply #3 on: November 15, 2009, 05:13:38 pm »
He didn't say he was switching to EFI.

He didn't say he wasn't either... The TBI pump is ok as long as he uses a pressure regultor.
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74 GMC, 75 K5, 84 GMC, 85 K20, 86 k20, 79 K10

Offline eisenhauer01

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Re: 87 EFI Fuel Pumps into Dual Saddle Tanks??
« Reply #4 on: November 15, 2009, 07:38:32 pm »
well, i am not sure which way i will go with it.. I am planning on doing a decent 350 build, i am not 100% on that though either.. just the way i am leaning.. might go with a little bigger motor idk.. anyways. I am leaning towards carb however i do it. I like the TBI, there was a  crate 350 tbi in my 84 k5 blazer i had when i was 16 and it was great, i didnt have any problems out of it and it started right up everytime. I kind of want to go TBI or TPI would be cool, but I don't know how much room I have to work with on the computer side of things with a cam installed and other things i want to do on the build, thats why i am leaning towards carb, because no matter what i decide to build the carb will do the job. But i was just asking about dropping the mech. fuel pump and going electric whichever way i go? Idk, maybe I should just keep the mechanical fuel pump if i go carb? right now the fuel tank selector valve isnt working properly so I only use the drivers side tank (which i noticed started leaking fuel.. slow drip, today) so i have to look into that.. sorry i am rambling. Anyways.  Any info on any of this would be greatly appreciated. I plan on lifting my truck 6" and running 35 BFG All terrains when it is all said and done, I just want a good strong dependable engine that starts right up. I am sure i will have to change gearing in the front and rearend as it is stock right now. any info would be greatly appreciated!! What do yall think?
1986 K10 Short Bed 4x4 305

Offline VileZambonie

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Re: 87 EFI Fuel Pumps into Dual Saddle Tanks??
« Reply #5 on: November 16, 2009, 08:03:39 am »
I prefer tbi over carb unless it's a simple ride you won't be using all the time or a weekend warrior. Tuning a tbi is pretty simple and they are CHEAP! Very reliable. I'm in the middle of a tbi dual tank conversion now on one of my projects.
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74 GMC, 75 K5, 84 GMC, 85 K20, 86 k20, 79 K10

Offline eisenhauer01

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Re: 87 EFI Fuel Pumps into Dual Saddle Tanks??
« Reply #6 on: November 16, 2009, 03:47:18 pm »
yea, that sounds really cool.. are you going to be using a 2 in tank fuel pump/senders setup or mechanical or what?  If tuning a TBI is pretty easy that is what I am going to do. I just didnt know how the computer would react to a mildly built 350 or whatnot. I just want to rebuild a 350 probably bored .030 over and a decent cam, performer intake manifold and headers, that would probably be about it. Would the stock computer be fine with that or would it need to be tuned somehow or what? How are you doing your build? thanks u guys have been a help already
1986 K10 Short Bed 4x4 305

Offline VileZambonie

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Re: 87 EFI Fuel Pumps into Dual Saddle Tanks??
« Reply #7 on: November 16, 2009, 05:41:38 pm »
All you need to do is change the PROM in the computer. On mine I am running two in tank pumps and senders. I got them from rockauto. I got the donor system from a suburban... there's more info here:

http://forum.73-87chevytrucks.com/smforum/index.php?topic=6233.135

I'm also converting my 75 Blazer to a TBI 462BB

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              ⌠ŻŻŻŻŻ'   [☼===☼]
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74 GMC, 75 K5, 84 GMC, 85 K20, 86 k20, 79 K10

Offline eisenhauer01

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Re: 87 EFI Fuel Pumps into Dual Saddle Tanks??
« Reply #8 on: November 16, 2009, 06:26:03 pm »
wow man, that post is awesome. I was reading along and i figured it was just a thread about some truck you built a while back then i realized on the last post by you about starting it was today. let us know how it goes. The specs on the engine build you put up look pretty good. Ok, I think that is what I want to do. I will have to find a doner  burb or blazer or 88 up truck. then i just need the computer tbi unit and wiring harness, then take care of fuel system and sensors. I am freakin ready to do this haha    ok a few questoins...

What kind of numbers do you think your setup will produce? (hp/tq)

You put vortec heads on your 86 350.. like heads off a 95 tahoe? how much difference in power or whatnot does this give?
will the vortec heads bolt up to any 350 block?

the fuel pumps you got from rock auto.. are they part numbers:
SPECTRA PREMIUM Part # FG05N
SPECTRA PREMIUM Part # FG05M

and do they go right into the saddle tanks? like the lock ring holds them in just like it does the senders in them now?

ok.. yea i know a lot of questions..  ???  thanks though!!!
1986 K10 Short Bed 4x4 305

Offline VileZambonie

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Re: 87 EFI Fuel Pumps into Dual Saddle Tanks??
« Reply #9 on: November 16, 2009, 06:44:18 pm »
Glad you like it. TBI was available in this body style 87-91 (R/V) models. The nice thing about a donor in this body style is it'll pretty much fall together fairly easily. The 88 up C/K systems will work too. Yes the fuel pump and sending unit will fit right into your existing saddle tanks. Vortec heads are cheap and easy and since I got em for free I had to put very little $ into them. I also have my own valve grinding system though. Yes they will bolt onto a non vortec engine. You'll notice the bypass hose in the front that's needed.
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                         /  _ _ _\_
              ⌠ŻŻŻŻŻ'   [☼===☼]
              `()_);-;()_)--o--)_)

74 GMC, 75 K5, 84 GMC, 85 K20, 86 k20, 79 K10

Offline eisenhauer01

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Re: 87 EFI Fuel Pumps into Dual Saddle Tanks??
« Reply #10 on: November 17, 2009, 07:35:12 pm »
ok, sounds cool. Yea i will definately need a doner vehicle. i was looking at different aftermarket options like Holley Pro-Jection and stuff like that but for what i want my truck to do i just need to find a doner k5 or burb 88-91. Then i could just swap everything right over.  I gotta fix my small gas leak and get my tank selection switch fixed. thanks for all the help vile
1986 K10 Short Bed 4x4 305