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L98 with a mech fuel pump?

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Old May 31, 2004 | 11:44 AM
  #1  
Trans_AM_88's Avatar
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From: NJ fo0
Car: 1986/88 Frankenstein Trans Am
Engine: carbed L98
Transmission: T-5
L98 with a mech fuel pump?

1: can i just slap a mechanical fuel pump on an L98? someone told me that the hole for it is blocked off.

2: whats mechanical fuel pump should i get? does a napa one suffice of should i get a holley or edelbrock?

3: do i need to get the pushrod also? or does the fuel pump come with one? cuz the L98 doesn't have one right?


thanks
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Old May 31, 2004 | 11:49 AM
  #2  
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From: Cincinnati, OH
Car: '90 RS
Engine: 377 LSX
Transmission: Magnum T56
A mechanical pump will never supply the PSI you need for your L98. However, unless you go carb.
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Old May 31, 2004 | 11:52 AM
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From: NJ fo0
Car: 1986/88 Frankenstein Trans Am
Engine: carbed L98
Transmission: T-5
sorry forgot to mention it's carbed already
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Old May 31, 2004 | 12:42 PM
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From: Philly, PA
What you need:

1. Fuel Pump. I like the Carter 6 PSI street pump @ 110 GPH, but there are many good aftermarket ones to choose from.

2. Fuel Pump Pushrod. Not supplied with the pump.

3. Fuel pump plate from a carbureted engine. Your stock one is a solid plate with no place for the pump lever arm to stick through inside the engine to contact the pushrod. A carbureted engine plate has an oval-shaped hole in it for the lever arm to stick through but is otherwise identical.

4. two gaskets- one that seals the plate to the block and the other that seals the pump to the plate. The pump-to-plate gasket is typically supplied with the pump. The plate-to-block gasket you can buy separately or just use a thin smear of RTV to seal it up.

Yes, your L-98 roller cam has a fuel pump eccentric to drive the pump and yes, the fuel pump pushrod hole is present in the block. It's basically a bolt-on.

Last edited by Damon; May 31, 2004 at 12:45 PM.
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Old May 31, 2004 | 01:50 PM
  #5  
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Go buy a stock replacement fuel pump. It will supply more than enough fuel for your engine up to 400hp.
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Old May 31, 2004 | 04:43 PM
  #6  
8Mike9's Avatar
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From: Oakdale, Ca
Car: 89 IrocZ
Engine: L98-ish
Transmission: 700R4
I can do a quick look on my block, but I don't think the L98 has the hole casted in it to add a mech fuel pump.
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Old May 31, 2004 | 09:29 PM
  #7  
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From: NJ fo0
Car: 1986/88 Frankenstein Trans Am
Engine: carbed L98
Transmission: T-5
Originally posted by 8Mike9
I can do a quick look on my block, but I don't think the L98 has the hole casted in it to add a mech fuel pump.
yeah let me know
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Old May 31, 2004 | 09:46 PM
  #8  
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From: Grand Rapids, MI
Car: Z28
Engine: Sb2.2 406
Transmission: Jerico 4 speed
Axle/Gears: Ford 9" 3.60
What does the car run on now? Or doesn't it run yet?
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Old May 31, 2004 | 11:25 PM
  #9  
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Man, I would think that it would. My brother had a '96 350 block, and it still had the mechanical pump hole there, just blocked off.
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Old Jun 1, 2004 | 10:59 AM
  #10  
8Mike9's Avatar
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From: Oakdale, Ca
Car: 89 IrocZ
Engine: L98-ish
Transmission: 700R4
Originally posted by 8Mike9
I can do a quick look on my block, but I don't think the L98 has the hole casted in it to add a mech fuel pump.
Well, color me wrong, there is a blockoff plate down there.
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Old Jun 1, 2004 | 12:13 PM
  #11  
Trans_AM_88's Avatar
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From: NJ fo0
Car: 1986/88 Frankenstein Trans Am
Engine: carbed L98
Transmission: T-5
so that means no mechanical fuel pump right? damn. i have a blue holley electric pump but the damn thing is so loud i can hear it running inside the car
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Old Jun 1, 2004 | 03:05 PM
  #12  
8Mike9's Avatar
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From: Oakdale, Ca
Car: 89 IrocZ
Engine: L98-ish
Transmission: 700R4
Originally posted by Trans_AM_88
so that means no mechanical fuel pump right? damn. i have a blue holley electric pump but the damn thing is so loud i can hear it running inside the car
This means you can install a mechanical pump...do as Damon posted above.

Is the only reason you want to switch is because of the noise?
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Old Jun 1, 2004 | 06:34 PM
  #13  
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From: NJ fo0
Car: 1986/88 Frankenstein Trans Am
Engine: carbed L98
Transmission: T-5
yeah pretty much. i think it's because there is no return line. a AFPR with return line is like $100
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