not sure about timing keys, probably talk to somebody like bender, i just use them for refrence since they are not far from me in ny. any speed shop could tell you, i have heard of and im gonna try this summer using the srx cdi for less advanced timing, as for cooling you can justs use an opticool head gasket, and have heard of people modifying srx heads or getting aftermarkets, allows you to equall compression of all the cylinders with the tripple pipes. instead of staggered compression like stock vipers use. most people with this setup uses srx pipes also but im using benders cause i dont wanna cut up my hood to make em fit, and they run close to the stock rpm range like the stock srx pipes. havnt found all the pros and cons for ya yet though, i just had back surgery so im not doing much right now, after i am gettin around in the garage bein bored again im gonna start this project this summer. good luck