Hi all
I am rebuilding my '68 400 engine and was wondering which quadrajet 4 barrel carby was standard fit to my car.
I am thinking of tracking one down and i'd like to know what part number it is or which other model will work properly.
The local Holden V8's of similar era were also fitted with this carby but are of smaller cu in(253,308)
Thanx for your help
Chris

Manual or automatic trans? 400HO, or standard 400?

The carb numbers for a 1968 can be found here; https://firstgenfirebird.org/firebird/1968/id_numbers.html

auto std 400

7028264

As nobody has addressed the second half of your question:

Just about ANY quadra-jet will work properly, and in my opinion, deviating from original part # should be seriously considered. Assuming it is rebuilt properly and certain modifications are done, they all have the potential to flow the exact large amount of air and fuel. It is possible that there is little to fear from getting one from a smaller engine'd Holden (keep in mind I personally know NOTHING about Holdens...but often a q-jet is a q-jet), but the carb off a smaller engine may or may not need some basic (and often entirely free) mods to get it to flow enough air to make a 400 perform strong. Keep in mind that an awful lot of used quadra-jets have problems with warping, and this is important to consider if you're buying a used carb from unknown source.

The previous part number is good info if having a #'s matching carb is your priority from a collectible car standpoint. But if you just want your car to run well and #'s matching is not important to you, then I believe you will probably be money ahead and actually have a better chance of getting your car to run really well by getting a newer Quadra-jet from a completely different vehicle. Loosely speaking, the early Q-jets had some design issues that were corrected in later models. For example the Q-jet on my 400 happens to be pulled from a 1976 GMC pickup. It needed a few minor mods and a rebuild, but it's absolutely awesome.

There are entire books written on the subject of "which Q-jets are best", and "how to pick one" and "how to make them better"...and one of the best is this one:
http://www.amazon.com/Rebuild-Modify-Rochester-Quadrajet-Carburetors/dp/1932494189

Hi
Not after original carby,looking for a good replacement,
Can i buy a new one that will work ?
I have a holley atm on an edelbrock rpm manifold