Would a Holley 112-578 throttle body be good for a nitrous sb race motor? Is there a better option? New to fuel injection and thinking of starting to collect some parts to get the conversion started.

Nice! Once you get the tuning figured out it will be worth it's weight in gold.

That is just the throttle body for a multi point..
I went with this one... its the 4150 base.. 1000cfm
http://www.summitracing.com/parts/hly-550-500
or if you want to use a 4500 base they have this one
http://www.summitracing.com/parts/hly-550-501
you still have to buy injectors and the pump... talk
to Monte for a price.. he helped me out
EDIT
also being that its a dry throttle body its just
air so its more air than the same size as a carb
thats moving both air and fuel

Gonna try to technology huh old man??

Check out the MS3PRO, more features than the holley and less money.

MS3PRO.COM

I have a holley cast 4150 Throttle body, not as low profile as some of the other ones but less expensive.

Need a 4500 throttle body as all my intakes and nitrous plates are 4500.

My buddy has the MS3PRO and wow, that is bang for the buck!!

Brad check out the new stuff from FItech too, good thread on the bullet about that

FWIW...I'm freshening up a 434" SB Chevy out of a friends boat. It had FAST XFI on it, but now he's changing over to FITech and gonna have Kevin Mullins tune it.

I have the FITech unit on order. $150 rebate + Summit 10% wasn't a bad deal. Should arrive next week. Evidently the Throttle body only flows ~850, which should be OK for me, but might be a deal breaker for a fast guys. Evidently they do not offer much tuning support via the advanced software, and I am a little afraid of what the interface will look like, I have yet to find anyone that has messed with it.

Cheaper systems are great.............until you can't get any support or find any help that knows anything about them.

Several on the net rave about Mega-Squirt......YET, to see one on a fast race car. Probably a reason for that

MS is not plug and play, nor is it something you can get into if you don't have the desire to learn and understand how the system works. Not a great choice if you're looking to plop something on and go.

Monte there is not a down side to running a 2000 cfm throttle body on a 420 cu in small block?

No.........you can NOT over "carb" an EFI engine per say. It only uses the air it needs. Makes no difference how much TOO BIG throttle body seems for requirements

I have seen EFI small blocks with 4000CFM of throttle bodies on a tunnel ram

The only exception I have to what Monte says, would be light throttle driveability. I know this is a race engine, and not a big concern, but going to big on a throttlebody (and I mean way to big)can make real world driving tricky. It can be difficult to get throttle enrichments just right, and the throttle cable "cam" usually needs some mods to be able to have fine foot control.
And as far as the holley efi... I am sold on its effectiveness and capabilities. I've used MS stuff(never the 3 though) and find it hard to believe that it is more capable than the Holley.

Most throttle bodies have the option to be one to one, or progressive on the linkage. We set up all drag cars one to one......BUT, if you wanted easier drivability with a big throttle body, you could opt for progressive. I have two HUGE throttle bodies on my jet boat, on a fairly mild 500" motor. I set the linkages up progressive and throttle control is VERY good

As far as EFI, guys like what they like and what they like, tends to be better than everything else to THEM. I have tuned cars with Motec, Holley, FAST, Big Stuff, Accel, Hal-Tech, Fuel Tech, Mega-Squirt and some others. I have YET to see anything more versatile and easier to work with than Holley. Not saying that because I work for Holley either. Every racer I have talked to that switched to Holley from what they had, can't believe how easy it is to use and how much more it does than what they had before. Now Motec, is probably the most advanced system out there, but you need a PhD to be able to use it all......LOL!!!

For "power adder" controls, nothing and I repeat NOTHING is as versatile as Holley. Not even close

Thanks Monte.