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Jetstarjockey · 05-23-2006, 09:32 AM

Hi Dan, Thanks for the reply ! I have researched the Olds Small Block design and have discovered that all small blocks have a 3.385 stroke. I am lucky to have a forged crankshaft version in my 1964. The bore for the 330 is 3.938 and the 350 is 4.057 . The compression height on both pistons is 1.615 . I am hoping that the 330 block can recieve an overbore of at least .119 to facilitate the use of 350 Olds pistons rather than a .030 over . I found one source that claims the 330 will accept a .125 overbore with no problem...and I am hoping that someone here can confirm this . I suspect perhaps the 350 piston may be more common than the 330 and I would also benefit from the extra displacement and oversquare B/S ratio. Also, I have found plenty of info on the later SBO heads but nothing on the #1 heads that I have on my engine. I have ported several sbc heads with good results and would like to try the same with the Olds, but would like some opinions on the potential of the #1 head to post decent flow values after porting. I am hoping for about 240 cfm intake port to enable a 400hp build-up? I have just finished building a 1970 455 with ported E heads and will be using that engine in my Jetstar until I find a 71 Cutlass convertable for the Big Block. The 330 will be going back in the Jetstar eventually and there is no hurry to get it done at the moment. What I hope to achieve is a stock looking small block with 400+ horsepower in a large "slow appearing" classic ! I Think I have been bitten hard by the "Olds bug" and look forward to chatting with others here, and sharing my discoveries as they unfold !

Thanks very much for your help Dan, I am heading over to the site you mentioned for a look !

05-23-2006, 09:32 AM	#3 (permalink)
Jetstarjockey Junior Member Join Date: May 2006 Posts: 4	Hi Dan, Thanks for the reply ! I have researched the Olds Small Block design and have discovered that all small blocks have a 3.385 stroke. I am lucky to have a forged crankshaft version in my 1964. The bore for the 330 is 3.938 and the 350 is 4.057 . The compression height on both pistons is 1.615 . I am hoping that the 330 block can recieve an overbore of at least .119 to facilitate the use of 350 Olds pistons rather than a .030 over . I found one source that claims the 330 will accept a .125 overbore with no problem...and I am hoping that someone here can confirm this . I suspect perhaps the 350 piston may be more common than the 330 and I would also benefit from the extra displacement and oversquare B/S ratio. Also, I have found plenty of info on the later SBO heads but nothing on the #1 heads that I have on my engine. I have ported several sbc heads with good results and would like to try the same with the Olds, but would like some opinions on the potential of the #1 head to post decent flow values after porting. I am hoping for about 240 cfm intake port to enable a 400hp build-up? I have just finished building a 1970 455 with ported E heads and will be using that engine in my Jetstar until I find a 71 Cutlass convertable for the Big Block. The 330 will be going back in the Jetstar eventually and there is no hurry to get it done at the moment. What I hope to achieve is a stock looking small block with 400+ horsepower in a large "slow appearing" classic ! I Think I have been bitten hard by the "Olds bug" and look forward to chatting with others here, and sharing my discoveries as they unfold ! Thanks very much for your help Dan, I am heading over to the site you mentioned for a look !