Yesterday a guy I know asked me if I was interested in a '58 GMC 270 six.... for free. Today I went to get it with 51Bolt and it got better. It's not a GMC 270 but a '58 261 with McGurk pistons, dual valve springs, Edelbrock dual intake w/ Rochesters. It turns free and the guy says he pulled it from his 38 Chevy Coupe because he was tired of it not starting when it was hot. Here are some questions: 1.Is this a car 261 as it has no oil filter? The only open fitting is on the drivers side aft where the oil pressure sender would be. The plug for full flow is flush with the block (I think). 2.The head is an 850 dated 1957 but the head bolt in the hole directly behind the small pipe plug in the left side center of the head has a slot in it and it is drilled for oil flow. I have the original 261 that came in my 62 1/2 ton and its head is also dated 1957 but no slotted bolt. I know it oils fine because I have started it and broken it in. (No body yet so I can't drive it). What would be the difference between the two? 3. The manifold carb studs are spaced for type 2 carbs and one of the carbs numbers can be matched to that on a 216. The other is sized the same Is this combination (2 small 1 bbls) O.K. to run on a 261? The guy said it was a really strong motor the way it was set up. I know you guys have all the answers so thanks.