First off, you wanted to know what you have a 230 or 250. The best way I know is pull a sparkplug and bring that piston up to or close to TDC . Shine a flashlight in hole and look at top of piston. Flat top with valve reliefs =230 and a dish shaped top piston equals 250. If you have off set motor mounts side to side your a lucky man cause you have a 292. I believe they would fit but can affect you in different ways. Possibly the number of grooves on balancer for belts 1vs2 , timing mark on balancer ( I've seen the indicator tab on timing covers on the right and left side) which makes the mark on the balancer in a different position. I know the 250 has two different balancers. It has to do with the v groove belt spacing which is different after 1975. Hope this helps!!
