Tahiti built a lot of boats in the seventies,the 18 footer was probably the most popular with big blocks,they built 21 daycruisers as well,and I remember a 27 foot adventure by them .A friend of mine had an 18 footer with a 454 Chev and berkeley jet, he was happy with his boat,it handled rough water well,except for the relatively low freeboard.After a long time he decided to change it to V-drive,that gave him more speed and better economy,but he was on the edge with the prop,since we have a lot of logs up here on the Fraser river where he boated most.He is an aluminum boat builder ,so eventually sold his Tahiti and built a 21 foot tin-can boat with a BBC and ugly Hamilton pump.He can barge a big moose ,but no performance like the Tahiti.Tahiti's were on the ligther side so they perform very well with a BB engine.I think the deadrise is 17 degree ,but I may be wrong.