Steve Moskowitz Posted April 20, 2015 Share Posted April 20, 2015 Taking the lazy way out, what is the easiest way of identifying whether you have a 303-371 or 394 engine? Just not my era of expertise! Link to comment Share on other sites More sharing options...
Tedd Thompson Posted April 20, 2015 Share Posted April 20, 2015 (edited) Print this and take it with you. This will give you the casting numbers of each year but a easy way is by the head numbers if original to the engine 303 ci 49- 52 no head number head not marked 303 53 is #3 324 ci 54 is #7 324 55 is #8 324ci 56 is#10 57-58 371 is 17 394 ci is23....... there are others but this covers most ..Tedd http://musclecarclub.com/members/castingnumbers/Oldsmobile1.shtml Edited April 20, 2015 by Tedd Thompson (see edit history) Link to comment Share on other sites More sharing options...
Steve Moskowitz Posted April 20, 2015 Author Share Posted April 20, 2015 Thank you!!! Link to comment Share on other sites More sharing options...
D Yaros Posted April 20, 2015 Share Posted April 20, 2015 While not foolproof by any means, at least in 59 & 60 the 371 engine was gold, while the 394 was green (even though Bill Hirsch calls it turquoise.) Link to comment Share on other sites More sharing options...
Tedd Thompson Posted April 20, 2015 Share Posted April 20, 2015 While not foolproof by any means, at least in 59 & 60 the 371 engine was gold, while the 394 was green (even though Bill Hirsch calls it turquoise.) Quite a few exceptions, 303's and 324's were green and 57-58 were also gold then the hi compression 394's were a reddish orange. Some of the late 371's were in fact a under bored 394's. There were industrial engines with setups for natural gas or propane, one I've seen was black in color but could have been painted years ago. Then there were the export engines that usually were lower compression units than what was put out for domestic use. I believe they also were turquoise....Tedd Link to comment Share on other sites More sharing options...
Steve Moskowitz Posted April 20, 2015 Author Share Posted April 20, 2015 So, this engine is in a race car. I was told it was a 303 from a 1952 98. Looked at the heads and can find no casting number and the engine serial number has been painted over with a very think coat of black engine paint. The car was written up in some articles as a 394 but I am doubting that........... Link to comment Share on other sites More sharing options...
Tedd Thompson Posted April 20, 2015 Share Posted April 20, 2015 A quick look at the valve covers will tell you if it's a 394 or a 303. The 303 has only two hold down bolts on the top of the covers while the 394 will have 5 maybe 6 around the bottom rim of the cover like a late model Chevy 350...Tedd Link to comment Share on other sites More sharing options...
Larry W Posted April 20, 2015 Share Posted April 20, 2015 '57 & '58 371's have only two bolts through the top of the valve cover, whereas '59 & '60 371's have multiple bolts around the perimeter. Link to comment Share on other sites More sharing options...
Tedd Thompson Posted April 21, 2015 Share Posted April 21, 2015 '57 & '58 371's have only two bolts through the top of the valve cover, whereas '59 & '60 371's have multiple bolts around the perimeter. Yep, that's why they are called a small bore 394. everything is the same as a 394 block except the bore diameter....Tedd Link to comment Share on other sites More sharing options...
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