Chevy engines belong in blazers, keep your 258, they can be an awesome engine. I put a holley 470 TA 4 barrel on mine with an offy intake, comp cam, 4.0 head, rollor rockers and the list goes on. This thing screams, it was a fun build and it's still all jeep. The holley TA series cars are made for off/road, it will take more angle than I care to give it. Good luck on your project, stay at it, spring is comming!!!!
1987 wrangler, 258 I-6, 5-speed.
2007 liberty sport 4X4, automatic
2009 ford ranger 4x4 FX4 OFF/ROAD, 5-speed