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| | | | Joined: Oct 2005 Posts: 25 New Guy | | New Guy Joined: Oct 2005 Posts: 25 | Hi gang,
Im sure this has been asked several times befor but I cant find anything on this topic at the moment.
I'm building up an old Military 302 GMC engine out of an M211.
I got lucky and found new 020 pistons and rings and have the short block all done.
I have a freshly rebuilt 248 cylinder head (New Style for flat top pistons) that I was planning to use on the 302 rebuild.
I know that the 235 chevy heads had a few steam holes that needed to be drilled when swapping with the 261, are there any similar considerations that I need to look for when swapping heads between the new style 248 and big bore Jimmy?
I also used the oil pan from a 1959 3/4 ton GMC pick-up with a 270, the 270 in this case had no dip-stick, are they a 6 quart capacity oil pan?
Thanks for any help and Merry Christmas!
| | | | | Joined: Jan 2008 Posts: 4,961 'Bolter | | 'Bolter Joined: Jan 2008 Posts: 4,961 | The 248 head will fit, but it has smaller ports. You will have to use a 248 or 270 intake manifold and then you are stuck with not enough carburetor. It will run, but you won't be enjoying the full potential of a 302. The 270 pan will work, but you will have to use the 270 oil pump also because the military probably had the deep oil pan. The 270 pan is 8 quart and close to 9 with an oil filter. Pour in 8 quarts and mark a stick and you will be fine. | | | | | Joined: Dec 2004 Posts: 1,897 Shop Shark | | Shop Shark Joined: Dec 2004 Posts: 1,897 | A 819 head will work, but the 983 head is preferable. Both of these heads have a "D-Shaped" combustion chamber. Using the 819 head on a 302 will raise compression a bit, but lose flow as Ken mentioned. No other head casting will work with the military 302 pistons. Any head can work with expensive custom pistons. The 417 head is the favorite of many racers, but it would require custom pistons to match. | | | | | Joined: Oct 2005 Posts: 25 New Guy | | New Guy Joined: Oct 2005 Posts: 25 | Thank you gentlemen,
Yes I used the 270 pump along with the pan, 8-9 quarts, thank you.
I did in fact wonder about the 248 manifold ports (I havent even looked at the 248 head for quite a spell).
I wanted to run a two barrel carb for sure, so looks like Ill just have the 302 head redone.
Merry Christmas everyone! | | |
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