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Discussion Starter · #1 ·
What is the recommended fuel injector size for a 383 setup? Also, at what point do you need to upgrade the fuel pump to a higher volume one? Thanks in advance for any input guys
 

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Depends on how aggresive your combo is, could range from 30 to 42# injectors needed.

Either way, a upgraded fuel pump is a must IMO. Walbro 255 or aeromotive 340



 

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Discussion Starter · #3 ·
To be more specific this is going to be a stock cam engine (for now) until I do more research and have a better understanding of cam ratings. I do realize its best to do everything at once but this is my chance to get my short block straight since I am rebuilding after a spun bearing mishap
 

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to answer your question simply though, a mild street 383 (i.e. not a giant race gam) revving under 6500, ~32lb injectors.

with the stock cam on a 383, the stockers would be almost enough, since that thing is going to be so choked out on the mid to high end, you wont even want to run it there.
 

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Discussion Starter · #7 ·
Thanks for the info guys, I would do everything at once but this is my only car and I've been riding my bike to work and bumming rides when the weathers bad for a month now Lol, lost 10 pounds!

So like i said this is my chance to get the bottom of the motor squared away, then start saving for a cam/head swap which will probably be done next year
 

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......What dictates injector size
camshaft,
cyl. heads,
throttle body size.........
A combination of all of the above.

The engine is basically a 'high-rent' air-pump.

The more air the engine can pump/flow, the more fuel you'll want to feed into it. If just one of the factors you named is a restriction, the whole system is restricted.

But if all three factors are enhanced, then you'll have more than stock level airflow.; at that point, you'll want to go with higher capacity injectors. How much bigger is determinded by how enhanced the total system has become.

A good tuner can tell you exactly what size injectors would be best for any given system. The rest of us just SWAG it, based off experience.

KW
 

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op

as KW said, you don't need larger injectors just for your 383 bottom end with stock cam/heads. wait until you do heads/cam/larger TB

if your 383 shortblock was made "internal" balance and not external like stock...you need to have a neutral balanced flexplate or flywheel
 

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Discussion Starter · #15 ·
op

as KW said, you don't need larger injectors just for your 383 bottom end with stock cam/heads. wait until you do heads/cam/larger TB

if your 383 shortblock was made "internal" balance and not external like stock...you need to have a neutral balanced flexplate or flywheel
ok cool thanks man, I figured since a 383 is pulling 33 more cubes that I would at least have to do some injectors and fuel pump, but it makes sense that if you have one restricted element in the top end that the rest suffers because of it.
 

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Discussion Starter · #17 ·
I'm curious what you're planning for the bottom end? I'm not trying to throw you under the bus. Everyone here can really help you out with part selection, dealing with your builder, and budget.
Actually if your from the detroit area i could tell you which shop is doing the work, I'm from downriver myself

The shop that is doing my work is Fast times racing in southgate, came highly recommended from my buddy who went to UNOH and works at livernois racing

$400 for the proper block work, $900 for the stroker kit (eagle cast) don't murder me folks for not going forged Lol. Those prices are with installation, balancing etc.

The main focus is to get my car back on the road as soon as I can because its my only vehicle, but shit I might as well do SOMETHING while its out

I want to go 383 because there is only a 300 dollar price difference between that and a 355
 
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