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Old 08-22-2017, 01:33 PM   #1
copper98
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98 rcsb build with stock injection

Looking for info on getting the most out of a stock L31/350 with stock/spider injection system. Just bought the truck and as best I can tell is basically stock. The owner I purchased it from had no info on truck. It is catalytic converter delete with duels and aftermarket exhaust.(not sure of brand) Other than that, who knows... I'm sure this has been asked before and I have searched and taken note of tons of possibilities. Money is not really and object(to a point) . It will not be a daily driver but I would like to keep the daily driver dependability. Just a weekend cruiser that will be running high octane pump gas. Interested in cam, head work, valve work, trans work, you name it I'm interested! Truck is in shop now having front end work done and a complete check up. Would also like to spray 50-125 shot so please keep that in mind with any info you give.
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Old 08-23-2017, 01:27 PM   #2
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Re: 98 rcsb build with stock injection

400hp is the max, however you get there. NOS is a terrible idea. If money doesn't matter then convert to marine intake.
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Old 08-24-2017, 12:08 PM   #3
copper98
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Re: 98 rcsb build with stock injection

I haven't been able to find one of these intakes off the shelf ready to install. From all I could gather they require an amount modification. As it usually goes, where money is not an issue time is nonexistent.
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Old 08-24-2017, 12:41 PM   #4
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Re: 98 rcsb build with stock injection

Why would that matter when you want to modify everything else on the truck?
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-78 c10 short/step: 388cid, M20, 5/5 drop, lots more. Playtoy and first vehicle.
-98 c1500 x-cab: 5.7L, 17" rims, 5/6 drop, flowmaster, helper bags,NBS rear disk brakes.
-02 Suburban 4x4: leveled front
-CBR600F4i, CBR600RR, CBR1000RR, and standup skis
DISCLAIMER: I cant spell for the life of me.
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Old 08-24-2017, 02:39 PM   #5
copper98
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Re: 98 rcsb build with stock injection

I want to keep it fuel injected. If you are offering to build one, or if you know some one who can build one I'd gladly pay you. Once again time for me(and know how) to do this is pretty much out.
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Old 09-12-2017, 12:09 AM   #6
copper98
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Re: 98 rcsb build with stock injection

Anyone have any experience with these? http://westersgarage.eidnet.ca/injectors.html
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Old 09-12-2017, 03:11 AM   #7
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Re: 98 rcsb build with stock injection

Or these? https://www.fiveomotorsport.com/prod...h/?v=10071#srp
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Old 09-12-2017, 03:10 PM   #8
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Re: 98 rcsb build with stock injection

I think air flow/turbulence would be the limiting factor in the factory vortec intake manifold/plenum, not fuel flow.

I would recommend the upgraded injector unit, from SMP(standard motor products) or AC Delco.

If money is no object(you said its not), an intake manifold with real fuel injectors would be best(marine style or ram jet style, summit sells a kit for 1900)

If time is a problem, you can use your money and pay someone else to do it(I'm not trying to be smart)
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Old 09-12-2017, 09:44 PM   #9
copper98
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Re: 98 rcsb build with stock injection

I've looked pretty hard at the ramjet and it is most likely my best option, as I don't know anyone with experience with the marine manifold mods. 2 of the Westers units appear to have regular style injectors and not the poppet style which was why I wanted to see if anyone here had tried them or had heard anything good or bad. From what I had gathered from other threads on the subject, fuel was a limiting factor. I will be having almost all work done by someone else is one of the main reasons I'm here asking and trying to learn all I can. And remember I said money is no object "To a point" lol. I didn't take it as being smart. I appreciate your time and input. I do find it hard to believe that no one has done any successful engine mods to these L31's without completely changing the intake manifold. Keep in mind I'm not trying to build a prostreet truck here, just something that has some pep. 350/400hp(the more the merrier)
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Old 09-14-2017, 03:41 PM   #10
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Re: 98 rcsb build with stock injection

Quote:
Originally Posted by copper98 View Post
I do find it hard to believe that no one has done any successful engine mods to these L31's without completely changing the intake manifold.
Thousands have. 400hp is the max. Fuel is the limiting factor. Marine manifold is injected and easy swap when you want more. I've said all of this already in this thread.
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-78 c10 short/step: 388cid, M20, 5/5 drop, lots more. Playtoy and first vehicle.
-98 c1500 x-cab: 5.7L, 17" rims, 5/6 drop, flowmaster, helper bags,NBS rear disk brakes.
-02 Suburban 4x4: leveled front
-CBR600F4i, CBR600RR, CBR1000RR, and standup skis
DISCLAIMER: I cant spell for the life of me.
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Old 09-14-2017, 11:45 PM   #11
copper98
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Re: 98 rcsb build with stock injection

Yep, Totally read you on the marine intake thing, was just looking for other things to gain some HP. Thinks for all the info.
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Old 09-29-2017, 02:01 AM   #12
copper98
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Re: 98 rcsb build with stock injection

Well after about 103 hours of reading every post I could find on the subject I think I've decided on a parts list.
New AC Delco Injector Unit
VMAX Intake Spacer
Volant Air Box
LT4 Hot Cam
New Valve Springs
Long Tube Headers
Custom Tune
From everything I could gather for all the posts I've read this is about all I can do to this thing. If anyone has any other suggestions, or experience with this setup please feel free to comment.
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Old 09-29-2017, 05:41 PM   #13
Chris95GT
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Re: 98 rcsb build with stock injection

My 2 cents? Toss a 5.3 in it and sell your L31 while it still runs good.
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Old 10-01-2017, 10:00 AM   #14
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Wrong fuel injection to modify

I've had mine for 18 years.

You need to forget about using nitrous. Period. Next subject.

Even if you switch to the new style injectors (but still poor CSFI style) you're wasting time and money.

I've started to go a different route on mine with a RamJet intake and true SFI.

Another thing that is sometimes an issue is the Vortec heads have a true world limit on valve lift around 470. Some have found it to be as low as 460.
The cam you are interested in specs at 492. So you may run into interference problems.

I recommend the RamJet cam instead. They work extremely well with the L31 setup. I use it.

One more thing if you're going to stay with CSFI. No matter who's name is on the new style injectors, AC Delco, GM, BWD or Standard Motor Products. They are all made by Standard. Therefore you can save some dough by buying Standards like this:
https://www.amazon.com/Standard-Moto...products+fj504
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