[brazilman36]

Hi,
I just recently bought a '66 goat and am very happy. [img]/infopop/emoticons/icon_smile.gif[/img]
I was told by the guy who bought it that he had very limited info on the engine.
I did some searching and found m / 7M5 / 1011 on the heads and after alot of exhausting searching I found the heads to be 71/72 455 H.O.
But I am having the darndest time identifying the engine block. It is obviously not of the same year.
Can someone please please help me identify this engine block. I know that it is '74 or newer.
The code reads as follows: 395590 YW
I need to get as much info on that as I can, so I can detremine if it is worth spending the money to yank the motor and rebuild it.
Thanks,
Tony brazilman36@netzero.com

[brazilman36]

Hi,
I just recently bought a '66 goat and am very happy. [img]/infopop/emoticons/icon_smile.gif[/img]
I was told by the guy who bought it that he had very limited info on the engine.
I did some searching and found m / 7M5 / 1011 on the heads and after alot of exhausting searching I found the heads to be 71/72 455 H.O.
But I am having the darndest time identifying the engine block. It is obviously not of the same year.
Can someone please please help me identify this engine block. I know that it is '74 or newer.
The code reads as follows: 395590 YW
I need to get as much info on that as I can, so I can detremine if it is worth spending the money to yank the motor and rebuild it.
Thanks,
Tony brazilman36@netzero.com

[67rs6spd]

post the casting #and date code look on the back of the block should be able to see them if you lay on the engine (if its in the car)casting # TO THE LEFT OFF THE DISTRIB,DATE TO THE RIGHT

[Tom]

My book shows the 7M5 head being for a 1971 250 Horsepower 455.The HO heads are 197(or 191)for 1971 and 7F6 for 1972.It lists a YW block as being a 1974 215 or 250 horsepower block.

Tom

['ol Pinion head]

7M5 are '72 455 4 bbl D port heads std on SJ GrandPrix or Grandville engine, not 455HO heads. Your date code on them appears to read I011 aka Sept the 1st, 1971. '72 models started coming out 3rd week of Aug 1971. Unfortunately, next to no demand for these heads or 7L4's or 4X (big chambers) or 5I's.

[Robert Williams]

Tony,--what numbers or letters are cast on the top of the center exhaust ports? I have 2 1971 455 engines stored away and both have #66 cast on them. These are both 4-bbl engines, and the heads have pressed in rocker studs.

[brazilman36]

wow, thanks for the replies guys.
I mainly got most of my info from yearone's web site. I was hoping to find out more info on the block which does not match-up with the heads. The casting # on the front of the block is 395590YW
I will have to look closer at the intake manifold near the distributor area, but all I saw there so far is the numbers: 485428
So, it seems so far that I should not even waste my time on a rebuild and start looking for better items.
Thanks ,
Tony

[brazilman36]

ok,
I climbed into the engine compartment....LOL
I love old cars....
I used a wire brush and flashlight and found L123 on the opposite side of the distributor.
Dont know if that helps.
Thanks,
Tony

[Tom]

That date code shows the motor cast on Dec,12 1973 confirming it is from a 1974 car.

[chris spires]

Yep, it's a 74 block. Which is a good year block.The source I got my info from is Geeb's tech links on classical pontiac.(a TON of great info there!) It also said it was a 215\250 hp.You can always find different heads for that block.6x heads flow good numbers with porting, and they're easy to find. Try to find the 92cc heads, which have an'8' cast on them(according to what I read)I used them on my 67 catalina which had a 73' 455 and 6x heads,(off a 400), and that car will flat scoot!