[rumair]

i got to reading another thread and went to Wallace's site, which led me to question what i thought i have for a block. when we rebuilt my engine we disassembled it at a friend's house. this guy has seen hundreds of pontiac engines over the years and has a book with the various pontiac engine codes. he looked up the code on my block up in the book and said it was a 455 HO block that was a one year only option in the 1970 GTO. i remember this specifically, but i also think i remember that the code was a "YA". according to Wallace's site, the YA was offered in 72/73, and was certainly not a high performance option. can anybody help clarify this for me? i'm sure gary would not have told me about the one year only GTO option if it wasn't true, assuming he read the code correctly. does anybody know if the "WA" designation for 1970 was the block that came in the GTO's?

97 Trans Am WS6
Best ET: 12.13
Best MPH 114.6
74 Formula 455
Best ET: 12.02
Best MPH: 112

[rumair]

i got to reading another thread and went to Wallace's site, which led me to question what i thought i have for a block. when we rebuilt my engine we disassembled it at a friend's house. this guy has seen hundreds of pontiac engines over the years and has a book with the various pontiac engine codes. he looked up the code on my block up in the book and said it was a 455 HO block that was a one year only option in the 1970 GTO. i remember this specifically, but i also think i remember that the code was a "YA". according to Wallace's site, the YA was offered in 72/73, and was certainly not a high performance option. can anybody help clarify this for me? i'm sure gary would not have told me about the one year only GTO option if it wasn't true, assuming he read the code correctly. does anybody know if the "WA" designation for 1970 was the block that came in the GTO's?

97 Trans Am WS6
Best ET: 12.13
Best MPH 114.6
74 Formula 455
Best ET: 12.02
Best MPH: 112

[b-man]

The WA block came in '70 455 360 hp GTOs with #64 heads, it is a manual trans block code. The YA is the same engine for the auto trans cars.

The YA code was also used on the 'regular' 250 hp '73 455 automatic engines.

Let's go racing!
www.outlawpontiacs.com/members/B-Man2.php
www.outlawpontiacs.com/members/B-Man.php

[RicksGTO]

Hey Rumair, WA code was used for many different Pontiac blocks from the 60's and 70's, including the '70 455 used in GTO's. To be sure what you have, look at the back upper passenger side of the block for the 6 or 7 digit part number, should be 9799140 if its the '70 455 used in GTO's, or 483677 from early '71 or 485428 from '72-'73. Also the 4 digit date code should be near the distributor hole with first letter for the month, 2nd and 3rd digit for the day of the month and 4th digit for the last number of the year, so for example L170 would be Dec. 17th, 1970 Go to http://www.teufert.net/identify/identify.htm for more info. on most every block casting number for Pontiac engines, not to mention about any other Pontiac part number you could need.

[rumair]

thanks guys!!

97 Trans Am WS6
Best ET: 12.13
Best MPH 114.6
74 Formula 455
Best ET: 12.02
Best MPH: 112

['ol Pinion head]

Kind of getting in on this late, but thought I'd throw a few thing out to help clear up a few things stated above...

YA/YC was the '70 455 auto GTO code. Yes, a few '70 model YC's were built, have one in the rack.

As earlier mentioned, WA was the '70 455 GTO manual trans code.

'71 models did not use the WA code, but YA was a seldom seen 455 2bbl code for '71 Bonnevilles, thus there is a possibility that there could be a '70 dated YA that was something else than a '70 GTO block...

Without looking at the VIN stamped on front of a bare block, one can easily tell if such a block was a '70 model YA or '71 model YA. Above the two letter block code, is the asm number. All Pontiac V8 '71, 72, & '73 asm #'s start with a ( left hand parenthesis symbol followed by digits. The '70 model assembly number did not start with the (

Though Pete's book & many internet sites list the 97799140 block only as a '70 455 block, it was also used in the earliast of '71 455HO cars. The blue '71 Judge in PE this month is an example of just such a vehicle. I know of 6 other early '71 HO cars that also came with this original casting block. There are probably more as well.