so i was talking with a buddy about project boats and i told him about the 29 eliminator that is posted for sale on here, he told me that he wanted a newer boat because he thinks the newer hulls are faster, not that i can disagree with that. ok so i have a 89 baja sport 250, 21 year old boat, name changed to the 270 for 91-93? and then they replaced it with a 272 and later like early 2000s came out with the 275. ok, if i yank my motor out of my sport 250 and drop it in a newer 272 or a 275 am i gonna gain anything based on geometry? i am using baja for examples because thats what i own and know most about. from what i can see most it seems like the decks are changing more then anything and they are adding more options so rather then getting lighter they are getting heavier. i am not argueing either side, but i guess i kinda see your power combo being more of a factor then if i had the 275 over a 250 or 272, again using baja as a example.

Newer hulls are faster in general. Mainly because they are lighter. They are just as strong if not stronger due to new technology in materials.
A newer 28 Pantera will about run 3-5 mph faster than my 1996 did with the same power. The bottom is the same.

If you start comparing older hulls to newer stepped hulls, there is an even bigger difference. A 37 AT stepped hull runs 3-5 mph faster than a 32 AT straight bottom with the same power. I remember someone actually used the engines from their 32 and put them in a 37 and it was about 5mph faster in the 37.

i guess in my comparasin right now i was not looking at stepped hulls. the new 275 id 4400 pound dry while my 250 is 3950 form the factory dry, sure i thin it has 6 more inches but... this was also kinda more project boat so a new hull would be unlikely for the most part. chances are it would be early 2000s or later. you mention the bottoms are the same, where is the weight savings coming from? they are still using the same stringer and transom matrerials as far as i can tell?