Corey Sprock makes a bigbore kit for the 84/85 T3. I have seen his T4s run, they are BAD!! I will be picking up 1 of his 300 kits for my 87 T3 soon. I know his billet heads have interchangable domes which lets you play w/ compression a bit. He makes some awsome tecate parts.
http://www.tecateconnection.com/
MIK6 / Mike
TECATE RIDER, HASPIN SURVIVOR!!
Trikefest 02, 03, 04, 05, 06, 07, 08, 09, 10, 11, 12, 13, 14 and beyond
RAFFAs Ice-fest 09, 10, 11, 13, 14, 15
Pensyltucky 09, 12, 13, 14, 15
New England Ride 4/13