Sorry but i cant answer your questions, and this is why, beacuse the engine looks like this right now:

The reason im shooting for high is becaus i got like a 265or 268 in my 305(not sure) and its still asking for more power it runs awesome, so i want to give this 350(possibly a 355) a lot more power. I tried to get the most power out of this 305 with just parts that dont reallt involve pistons and heads and its not very powerful(for a 305,definatly, but no 350) so ima build this 350 and gain some powahhhh!!
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1978 Chevy Scottdale Stepside, 3rd engine- 350c.i. built with cam and lifters, holley 670cfm carb. and intake,heads shaved .60. Truck is a project, and I am its restorererer!