[joedoh]

those arent the right ones, they will work but you will need new mounts. transdapt makes specific v8 s10 mounts for a 4.3, on the 4.3 you have to take the lower clamshell mount off the frame and bolt it to the transdapt mount so that the mount goes rearward, on a v8 s10 application it would typically move the engine FORWARD.

it is important to get the 4.3 bellhousing in the right spot if you are planning to do a V8 swap, the 4.3 is a 350 with two less cylinders, so the exhaust manifolds will occupy the same basic space between the two engines and that is important for steering shaft clearance. you dont want to make your life easy with the 4.3 just to have to redo it with a 350.

getting the mount off the frame can be tricky, on early s10s the nuts are not captured and will just spin and spin if you try to remove the bolt from the topside. if you are replacing control arms it is much easier but still tricky to get up in the frame with swivels and get the nuts off. you will need to do this when reinstalling too, to mount the transdapt adapter. two ways I have heard to make life easier, one is to cut a window in the frame with a plasma cutter right where you can put in an open end wrench to hold the nut, the second is to drill a hole diagonally so that it just catches the edge of the nut and use your welder to dot a weld on the nuts in two places, welding only the nut and the frame but missing the mount and the bolt!

but your column a/column b choice here is, the mounts arent free (100 bucks last I looked) and 5.5 inches is just barely enough for some breathing room on a 4.3. it will be great with a 350 though, the 350 engine mounts are further rearward than the 4.3 so you will end up in the right spot, except that you will need that larger trans tunnel and will have to touch the trans crossmember and driveshaft a second time. column a/column b.