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**COBALT** · 07-10-2002, 11:49 AM

Yeah, you don't need to crawl under the truck to get block numbers. You need to crawl on top of it. The casting number is on the top of the block behind the driver's side head on the flat part where the bell housing bolts to the engine. You'll probably have to spray some brake cleaner or something back there to scrub the pad off. They're raised numbers. because of my brake booster I had to use a shaving mirror and a flashlight to read it. There was no way I was getting my head in there.

Then you need the number actually stamped into the block. 1972c10_ohio is showing you where it typically is. That's where mine was. It will have a code with letters and numbers, which end in a 2 or 3 letter suffix, like "TRW". That tells you where the engine was used and confirms (usually) whether or not it's a 2 or 4 bolt main.

Don't feel too bad if it turns out to be 327 heads. My 350 ended up having a 2bbl 327 manifold/carb on it.

07-10-2002, 11:49 AM	#7
COBALT Senior Member Join Date: Sep 2001 Location: Seattle, WA, USA Posts: 5,817	Yeah, you don't need to crawl under the truck to get block numbers. You need to crawl on top of it. The casting number is on the top of the block behind the driver's side head on the flat part where the bell housing bolts to the engine. You'll probably have to spray some brake cleaner or something back there to scrub the pad off. They're raised numbers. because of my brake booster I had to use a shaving mirror and a flashlight to read it. There was no way I was getting my head in there. Then you need the number actually stamped into the block. 1972c10_ohio is showing you where it typically is. That's where mine was. It will have a code with letters and numbers, which end in a 2 or 3 letter suffix, like "TRW". That tells you where the engine was used and confirms (usually) whether or not it's a 2 or 4 bolt main. Don't feel too bad if it turns out to be 327 heads. My 350 ended up having a 2bbl 327 manifold/carb on it. __________________ '69 3/4 ton C20 2wd-350ci/TH400 '69 3/4 ton Custom 20 2wd-350ci/4sp Manual '99 2wd 5.7 Chevy Tahoe Seattle, WA.