I have a 91 s10 blazer. 4.3l 262 tbi. Vin on truck has Z. So it's hard to find info online. I'm looking to replace the heads and intake manifold. I found new heads but they ask if there press in studs or screw in studs? Also it's asking if the heads are notched or not? I'm looking into the edelbrock manifold, or holley. Looking to replace all this soon, I have experience just need the info. If anyone has any links to this information/videos it would be very helpful. And help me with my questions! 4.3 1991 s10 blazer tbi!