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EFI For 68 383 Road Runner

Ray Bolden

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Please don't beat me up too badly as I'm a newbie when it comes to Mopars. I want to install a port EFI unit on my stock 383 engine but everything that I've seen is for the RB type engines. Is there a means to adapt an RB port injection unit to my 383 block? I'm thinking that I'll be stuck with a throttle body of some type. Please help!!
 
You will need to get a quality single plane B block intake manifold and have injector bungs machined/welded in it. Then everything else for the RB port injection works. The big companies see no profit in offering a B block TPI intake.
 
Thank you very much Diesel for your quick response and sharing your knowledge. That's kind of what I expected but had hoped there was an easier solution. Thanks again!
 
Thank you very much Diesel for your quick response and sharing your knowledge. That's kind of what I expected but had hoped there was an easier solution. Thanks again!
I have a 383, searched for yrs. Ended up going Fitech tbi. For tbi, I'd go Holley Sniper but that wasn't out when I purchased my Fitech. If I knew a good machine shop nearby, I would have spent the couple extra bucks to modify a single plane for tpi
 
I have a 383, searched for yrs. Ended up going Fitech tbi. For tbi, I'd go Holley Sniper but that wasn't out when I purchased my Fitech. If I knew a good machine shop nearby, I would have spent the couple extra bucks to modify a single plane for tpi
diesel, just curious, do the modern single plane manifolds like Victor or Indy with the cast bosses work for injector installation? My Indy version looks like it should.
Edit: just drill & tap for correct threads?
 
diesel, just curious, do the modern single plane manifolds like Victor or Indy with the cast bosses work for injector installation? My Indy version looks like it should.
Edit: just drill & tap for correct threads?
If the bosses line up w the runner and there's enough material, then yes. I'd give the manufacturer a call just to confirm, but most w the bosses should be able to be drilled n tapped. Or reemed or however the injectors are installed. There have been a couple articles out there on the subject. I was just being cheap when I did it. Little did I know that would have been a drop in the bucket on the project.
 
You will need to get a quality single plane B block intake manifold and have injector bungs machined/welded in it. Then everything else for the RB port injection works. The big companies see no profit in offering a B block TPI intake.

You're running a single plane intake, automatic or manual transmission? Was it worth the switch?

I'm considering the sniper setup on a dual plane intake with a spacer. All I've read on the Holley forums for the most part say this is the way to go when running a dual plane.
 
Contact Rich @ Fastman EFI
Screen Shot 2020-07-02 at 7.38.34 PM.png
 
You're running a single plane intake, automatic or manual transmission? Was it worth the switch?

I'm considering the sniper setup on a dual plane intake with a spacer. All I've read on the Holley forums for the most part say this is the way to go when running a dual plane.
Running dual plane Edelbrock RPM with 3/8 spacer. Stroked to 496, 440 Source Stealth heads fully ported, hydraulic roller cam. About 610 hp n 670 tq. 727 auto w custom billet torque converter n Gearvendor o/d. Still in the tuning stage.
 
Running dual plane Edelbrock RPM with 3/8 spacer. Stroked to 496, 440 Source Stealth heads fully ported, hydraulic roller cam. About 610 hp n 670 tq. 727 auto w custom billet torque converter n Gearvendor o/d. Still in the tuning stage.

That sounds pretty nice, especially with the gear gearvendor o/d. Is the throttle response noticeably better with the efi?

I running forged domed pistons on a higher compression motor with fully ported 906 heads, mechanical roller. Currently with a Wilson ported RPM dual plane and a 1" tapered spacer. Originally build had an M1 single plane intake, was running a standard RPM before the ported one.. The ported intake and spacer had a clear positive effect on the street. I'm considering the efi to really smooth it all out.
 
That sounds pretty nice, especially with the gear gearvendor o/d. Is the throttle response noticeably better with the efi?

I running forged domed pistons on a higher compression motor with fully ported 906 heads, mechanical roller. Currently with a Wilson ported RPM dual plane and a 1" tapered spacer. Originally build had an M1 single plane intake, was running a standard RPM before the ported one.. The ported intake and spacer had a clear positive effect on the street. I'm considering the efi to really smooth it all out.
Unfortunately it's still in the computer learning phase so I wont know how much better or worse for awhile
 
Please don't beat me up too badly as I'm a newbie when it comes to Mopars. I want to install a port EFI unit on my stock 383 engine but everything that I've seen is for the RB type engines. Is there a means to adapt an RB port injection unit to my 383 block? I'm thinking that I'll be stuck with a throttle body of some type. Please help!!

I don't see anything for the low deck "B" block. I though Indy might have a ModMan, but looks like they are made for the RB engine.
Indy does sell a EFI "kit" 400-F4-31 Link:
http://indyheads.com/images/price.2015.16.pdf

I think it is a modified 400-I4-2 intake modified with injector bungs?

It looks like you will have to pick a manifold (single plane) and install the fuel injector bungs.
I think the small pads on most of the intakes are just for nitrous oxide injectors.
You can get FI bungs that weld or screw into the intake, but the fuel rail will have to have the same spacing as the bungs.
As noted by 1 wild R/T, call Fastman EFI for an intake like in the photo.

For the cost, the TBI EFI units (Sniper / Fi-Tech) are pretty good and alot easier to wire.
The Fi-Tech came to market a year or two before the Sniper and I have the Go-EFI 8 1200 PA unit.
I wanted the timing control, and only some of the Fi-Tech have timing control. I think all the Sniper units come with timing control.

It seems that Fi-Tech wanted to "dumb down" the software to make it "easier", and they sort of have their own nomenclature that is a bit different than most EFI systems. So far the EFI unit seems pretty good, but I had a problem with their Hy-Fuel in-tank pump not having the correct submersible fuel line.
I like that this works with a factory lean-burn distributor on my 500" (499) stroked 400 block.

For a comparable price, the Sniper seems to offer more, and uses conventional EFI terminology.
I installed an entire Sniper system on Mikes 496" stroked 383. That was the Sniper fuel tank (Tanks Inc Tank and pump assembly), the TBI unit, and the HyperSpark Distributor and CD Box. It all seems to be working fine, but just got it done a few months ago, so not that many miles on it.
 
The cast bungs on my Indy 440 manifold are pretty big. I'd say a fair amount bigger than the Victor. I can't say if the 400 Indy is the same.
 
What 451Mopar said, the pads on the single plane are for nitrous. There are to parameters that need to be met. Injector bungs will need to be on exact same horizontal plane and injector rail needs to have injectors at same spacing. A "Good" machine shop could do it. But I'd rather not reinvent the wheel, Fastman EFI has already done it.
 
Thanks, trying to learn a little from those in the know, since I'm sure not.
 
I an not sure of the boss size on the Indy Intake? either way, you still have to modify the intake with machine shop accuracy.
 
Agreed, good point. I wonder if the injector spray should be in any special angle to to angle of the runner or if horizontal is OK?
 
Please don't beat me up too badly as I'm a newbie when it comes to Mopars. I want to install a port EFI unit on my stock 383 engine but everything that I've seen is for the RB type engines. Is there a means to adapt an RB port injection unit to my 383 block? I'm thinking that I'll be stuck with a throttle body of some type. Please help!!

At the moment nobody does an off the shelf low deck standard port EFI intake. The Indy intakes can be easily modified for port injection by drilling the bosses but their intakes are all MW size. So if you really want port injection on a low deck you have to roll your own. Not that big of a deal really, just call Wilson Manifolds and give them a credit card number and you'll have an intake in your hands within a few weeks. I have a Wilson intake on the low deck 512 in my Duster. It is a super high quality setup but it will cost you some money.
DSC_3640 (Large).JPG
 
If this is your first EFI rodeo you might want to just start with a Holley Sniper to get your feet wet. You can always step up to the port injection stuff down the road. I have a Sniper on my Coronet and there isn't really any performance difference between the $2000 Sniper and the $10,000 port injection setup.
 
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