[Rocky Rotella]

I'm beginning to compile information on the 1974 GTO for a future project. If anyone with a '74 GTO would be willing to provide some information, I would appreciate it. I'm looking for:

1) original block code (WP, YP, YS, or ZP)
2) head casting (46 or 4C)and secondary application stamp (same location as 6X)
3) rear axle ratio (2.73 or 3.08)
4) buildsheets and/or PHS information (please scan and email, fax, or send)
5) if your car had chrome splitters originally

Please feel free to email direct at jrotella@cox.net if needed or post here.

Thanks!

[Rocky Rotella]

I'm beginning to compile information on the 1974 GTO for a future project. If anyone with a '74 GTO would be willing to provide some information, I would appreciate it. I'm looking for:

1) original block code (WP, YP, YS, or ZP)
2) head casting (46 or 4C)and secondary application stamp (same location as 6X)
3) rear axle ratio (2.73 or 3.08)
4) buildsheets and/or PHS information (please scan and email, fax, or send)
5) if your car had chrome splitters originally

Please feel free to email direct at jrotella@cox.net if needed or post here.

Thanks!

[Goatguy]

Hey there!! 74 GTOs came with two block codes,WP for (standards) and (YP AUTO)All had 46 heads and a rear axle 3.08.1. Lots of info @ pontiacventura.com,Pontiac Historical Services can give you all the info on your car from the VIN# for 35 bucks.I believe they all came with the chrome spitters.

[Goatguy]

'DOH'!!! It seems that YS and ZP are also 74 GTO engine codes.The YS is auto trans with an HEI. the ZP also an auto.

[Rocky Rotella]

I don't own a '74 GTO but I have always liked them. I'm trying to nail down a lot of information around them.

All the '74 GTO's I've have seen over the years have had YS block codes, I've yet to find a YP code to date. I've got some very detailed Pontiac engine assembly documents that came from Engine Plant 9 that state the only difference between the YP and YS engine is the EGR valve. Every other part of the engine from carb to oil pan is the same. The ZP is California emissions and I beleive would have had 4C heads. I'll have to look at the documents for that fact.

I don't beleive HEI was ever available on the GTO as it was limited to L78/400 4bbl and L75/455 4bbl engines in 1974 and only after May 1, 1974 on a wide scale basis.

I'm also trying to verify if the G92 Performance Axle Ratio option was included with (or a required option) the GTO when teamed with auto trans. We know the manual trans GTO's received 3.08 gears but the Engine Application Chart shows 2.73 as the standard ratio with the 350 4bbl and A/C. 3.08 is optional. I'm trying to colect build sheets to verify that.

I appreciate the website link to

[poncho-mike]

Rocky,

I've parted out two 74 GTOs. This was done 10 - 15 yrs ago. Both cars had 3.08 posi rears, and one was auto with a/c and the second was a 4-spd. I think the only thing I have left is the shakers, which are probably put up somewhere. I sold the rears.

Mike

[ss47987]

In 1977 I bought a 1974 gto ,350,point dist.,4speed,3.08,with a/c, still have today.Now has 455,4 speed,no a/c ,3.55 12 bolt.This is one the many cars that I should have left stock.But wouldn't had been as fun.

steve smith

[Rocky Rotella]

Thanks for the information guys.

[Held for Ransom]

Rocky, I don't believe posi was standard. I do believe the chrome extensions were standard on GTO option, as there is no provision to order them on a PHS-enclosed Order Form (dated 6-19-73). A pretty good reference book is "GTO RECOGNITION GUIDE" by Paul Zazarine. I do have a manual engine from a '74 GTO and will E-mail you with the PHS on the car and code info.
From "1974 Pontiac Accessories":
GTO Package
Order Code 342 - UPC WW3
(2-dr. Coupes and Hatchbacks)
* Distinctive Grille w/Parking Lights
* Rally II Wheels w/o Trim Rings
* 350-cu. in., V-8, 4 bbl. Engine
* Dual Exhaust with Chrome Extensions
* Specific Shocks and Springs w/Front and Rear
Stabilizer Bars
* E70-14 Black Tires
* Outside Sport Mirrors
* GTO Identification on Deck Lid, Front Fender
and Grille Panel
* Functional Shaker Hood Scoop
* 3-speed Floor Shift

[gtoric]

Rocky,
I'll add my 2-cents worth on this subject...
My research tells me that the 74 GTO was built standard (A.T. or M.T.) with 3.08:1 diff ratio. With optional A/C, 2.73:1 was installed, unless the performance 3.08s were also optionally ordered.
Several sources, including the PMD Service Manual and Pete McCarthy, list YP as an optional A.T. engine. Your information stating that YP/YS was an EGR-equipped issue runs contrary to the MVMA Specifications that states all engines were equipped with EGR systems. Could one of these engines be equipped with C.C.S. or E.E.C.?
The factory order sheet does not list Chrome Exhaust Splitters as either standard or optional equippment. The Dealer's Sales Manual does list Splitters as a GTO-only item. My guess is that the splitters were included with GTO dual exhaust tail pipes for a time at the start of production. In this manner, they would not be listed as an option on the order form. I can't say how long they were installed by the factories.
I have an original build sheet that I can email a scan to you. The car was built in Van Nuys, CA early in the production run. It was equipped with a YS engine, ME (3.08) trans, and JB (3.08 ratio open rear end). It was Buccaneer Red w/Red Appointments interior option. It was also built with P06 Rally Wheel Trim Rings. Must have been a specially ordered option.
Do you have any build sheets (from any year) that you could send me in return?