nailhead block numbers

[mike sanmiguel]

I have an engine with the following casting #'s MR 290 6k117505. Can you tell what c.i. it is or any other info. It has a 4 barrel carb and stock air cleaner. engine is complete and still in a wildcat 2 Dr. HT. these numbers dont match any of the listings that i found on the buick sites. Help!

MIKE

[Dr. Frankenbuick]

Mike, I think I can help you. Were the #s from the front valley pan rail?

MR was the code for a 66 401 in a Skylark Gran Sport. It was called a 400 because of the 400 cubic inch limit in the intermediates, but it was a 401.

290 is the date code. The engine was built on the 290th day of 1966.

6 is for 1966.

K is for the assembly plant code. K was the Kansas City, Missouri code.

117505 is the car # in the series.

The actual casting #s are embossed on the back of the block in #s and Letters that are about 1" long. The #s you gave involve the production code and part of the serial # for the car. Yours tell us much more then the casting # would.

I hope that helps. I wonder if that is the long lost engine that came with my car?

[mike sanmiguel]

thanks for the information and the quick response. I will keep you informed on the tear down and rebuild on this engine. Hope it is in good rebuildable condition.
next i will need to I.D. the transmission and differential.

[4speed]

dr frankenbuick

I agree with your responce to mike, although i'm confused on your date code of 290. according to the calander the eng. would have been built on Oct. 15 or 16 of 66? could it have been Oct. of 65?
considering the low serial# on the block it would be an early engine.

[Dr. Frankenbuick]

4speed,

You may be correct. I am not sure if the series # is for the make or the model series (43000, 44000, etc.). If it were the car number for the make in the year, then it would seem right to be earlier. But, it would be a late production # for the series. Maybe you or someone else here knows definitively about the series # ? It really only matters in a #s matching car where the date codes need to be 2-8 weeks prior to the build date on the firewall data plate.

[BUICKNAILHEAD]

Originally posted by mike sanmiguel:
I have an engine with the following casting #'s MR 290 6k117505. Can you tell what c.i. it is or any other info. It has a 4 barrel carb and stock air cleaner. engine is complete and still in a wildcat 2 Dr. HT. these numbers dont match any of the listings that i found on the buick sites. Help!

MIKE

Hi there I just wanted to give you a link that is on this site that helps out quite a bit. I always use it and even have it printed out when on the move.
http://www.buicks.net/shop/reference...g_numbers.html

regards,

[66SkylarkGS]

Since we're on the subject.....I am new to the Nailhead arena and have a similar question. Based upon the MR and day of manuf code, I have a 66 Skylark GS 401 with an MR 5I2 .... (yes I as in "eye"), any ideas on how this fits into the Gran Sport scheme of things?

Any info would help.

=fubarGS