Earlier post on LTR vs. base TBI where they dyno'd each showed that the HP difference was really ~ 12-15 Hp not the 40HP advertised. If you think about it, Manufacturers have fudged the numbers up and down for years as a sales/marketing gimmick.
2001 camaro LS1 was rated at 325hp but routinely put more that down to the back wheels. Down rated primarily as the same engine was used in the corvette and couldn't have too close of a rating for marketing purposes.
If you think about it, the engines are really mechanically identical on the internals (cam, heads, comp ratio, etc.) so intake and exhaust and what makes the difference. TBI intake was pretty well designed and comparable most of the way up the RPM range compared to the LTR which breathed slightly better on top due to open plenum manifold. This was worth a few HP on top but how many would they sell if they indicated that the difference was only ~ 10hp?