Does anyone know where I can find the engine specs for a 400 HO? I want to build my 400 back to its HO specs. Thanks for the help.

The factory service manual will list ALL of the correct Pontiac part numbers for the cam, distributor, carburetor, etc. With that, along with a few other web sites, we should be able to steer you in the right direction on all the other external parts, such as correct heads, intake manifold, exhaust manifolds, etc. Most of the other internal stuff, such as the rods, pistons and cranks, are all basically the same for all 400 engines, except Ram Air 4.

When you say the "specs" on your engine, what is it exactly that you are looking for.

Also, what year is the motor / car?

Q

Q,

Thanks for the reply. The motor is a 68 and the car is a 68 coupe. The enternal parts (cam, pistons) of the motor have been modified so when I ask for spec I mean to say original cam size, etc. I didn't realize that the enternal HO components where the same, except for RA, as the standard 400s. Let me know of the web sites I can visit that will provide the info. Thanks.

The cam is the "068" cam. You can get the specs from www.classicalpontiac.com

Here's the direct link to the cam shaft cross-reference:

http://www.pontiaconline.com/restoration/cams.html

It's Pontiac Part number 9779068.

The heads should be #62,#16 or #216 (I think), depending on whether or not it's an automatic or a manual transmission.

The carb should be a Rochester Q-Jet model 7028270 or 7028273.

The distributor part number, alternator part number, etc is best retreived from the service manual.

Q

Q,

Thanks for the info and great web sites! The heads I have are 62s and its a 400 AT. I believe the rear gears have been modified as well. Do you know what the gear ratio is for the HO Birds? And are the exhaust manifolds standard? Thanks.

Now you're asking me questions I can't answer! I know that you could order virtually any gear ratio with almsot any engine, so there's no such thing as the "correct" ratio. About the manifolds, I would guess "Long Branch" HO manifolds are correct, but I will not actually say that I'm sure about that.

However, for $35 you can order copies of the original paperwork for your car from PHS. This will tell you exactly when and how your car was built, including all options and colors. That way you can restore it to factory-original condition, if you choose. PHS is at

www.PHS-online.com

Q

carb numbers for '68 400 HO Firebirds are:

MT 7028271
AT 7028264

Steve

D'Oh!

Of course! The 270 and 273 are the GTO carb numbers! I'm still in my GTO rut.

Thanks, Steve!

Q

That's the same motor my car came has, spec's are as follow's: There were two that year the engine codes were wq and yw.The wq engine.068 cam 16 heads 1-4 barrell carb. #7028271 yw code 067 cam 16 heads 1-4 barrell carb.#7028264 There's a great book in the back of any ames catalog it's called pontiac musclecar performance it list all the engine codes, intake codes, head codes etc

It's all good, Q!

Steve :p