Hey you have a build 4.5 from gtm right? if you don't mind me asking..how long did it take to build your 4.5? who did the installation and were you pleased with the power? im almost ready to pull the trigger on a 4.2stroker longblock from g.t.m, im kinda pressed for time just because i don't want my car down for 6mts..and they said they can get the 4.2built in about 8 weeks,im just debating on if i should wait the extra time an spend the extra $ to get the 4.5L. im already looking at 17k for the 4.2 im not sure how much more the 4.5 is or how much longer it would take, i asked sam while he was quoting me,but never got an answer.he just said the 4.2 would be faster an it's all i need.which is probably true,but if im already dropping almost 20grand an its only a lil more to get ALOT (notsure) more then i'd of course want to go bigger,lol. Thanks for the info,im just trying to get as much info as i can to put my mind at ease before pulling the trigger on such an expensive item,lol