Sorry it took so long for me to reply. I don't think to check my messages very often. I'm not sure obout converting a weber to a 2.5. Most of my coments are geared towards the 4.0 and 4.2 six cylinder engines as i've never been around the 2.5 much. Sorry that i can't help much. Only other thing i can think of is to find out if that engine was used in any older vehicles with carburators. I believe the 2.5 is a GM engine. Good luck.