I believe the 5858 is the updated version of the 49 as well .. I know from the precision site , the 5831 that is in they’re entry level category. It states that the 5831 is the “new “ ta44 .Yeah I get it. From this thread and many others I've read is stock turbo can take you far. "Stock down pipe has seen 11's" "get alky or E85 and keep everything" and so on. I'm just coming from the angle of -IF one has to replace a part, is there a suitable upgrade that without going overboard won't hurt performance but has room in it to expand. From my understanding a 58/5858 is the updated version of a TA-49.
I’m still waiting for a post where someone says , they went 10.90 on a flat tire , plugged cat & 2 missing plug wires .... but they ran a allky with a tune