73 74 SD Head bolts
 

Do the 73-74 Super Duty's use washers under the head bolts? It was pointed out to me today my 74 has washers under the factory bolts and was asked if it was correct.

I have heard this too. From a very reliable source.

Yes, that is certainly correct. It was limited to the SD-455 during the 1973 and 1974 model years. I don't know that they were used on any other Pontiac V-8s before or after.

great, thanks. I see the picture of the SD Engine on the cover of your book appears to show a washer under the bolts. Do you know of a replacement manufacturer? I have at least one that is cracked.

SD Washers:

http://forums.maxperformanceinc.com/...1&d=1515766770

:)

Excellent

The one I took apart had no washers. 1974 car heads never off till last year.

Do you have the block date and/or the car build date?

:)

I cant easily get the block or head dates codes, but I can faintly see the block casting number in a picture I've dug up it "appears" to be 1203. The Pontiac paperwork shows the car shipped to the dealer 5-10-74. Unfortunately the cast eagle crank in this block, installed by the prior owner, failed the thrust bearing test while doing a cam change. I'm having the motor gone through with a new forged crank, rods, etc..leaving no stone unturned.

At 1st I was going to say it probably is an 'I', but I have a lot of SD's at 'L' 203.

Probably the last batch of SD's cast?

:)

The closer I look at my fuzzy picture, it very well could be L203

Washers
 

421 SD Engines used head bolt and main cap bolt washers as well. :usflag:

Washers
 

These should work. :usflag:

ARP should be able to find the washers.

I purchased these from Fastenal. They are a perfect match.

https://www.fastenal.com/products/details/33405

Do they have to be a certain hardness rating?

The factory washers were definitely hardened.

There was a SD455 service block advertised for sale on this forum awhile back. I remember the cast date being March 1974.

I should have said last batch cast in 1973.

:(

While a lot of 74 SD cars still had 73 cast date blocks, later part of model run the 74 cast dates started.
I'd have to see when the 74 cast dates seemed to start appearing on 74 SD cars and the build date possibly.

:)