Here is a post about Boats that fly. It takes a lot to do it though because Buick Boats are heavy. http://www.v8buick.com/showthread.php?t=128608&highlight=fastest+boat
Your '70 Riviera GS is one of 37,336 (total production for that year), - of those, 3,505 had the GS handling option. Check out the Riviera Owners Association (ROA) at: www.rivowners.org
If you mean the factory rating that would not be correct in fact just on paper. GM jockeyed around with the paper numbers to keep within their 10 to 1 weight to horsepower ratings. So a 370hp rated 70 riv would have less grunt than a 360 hp rate 70 GS stage 1. The engine in a 70 Riv rated at 370 hp is the same engine as the 350 hp rated 70 GS Gran Sport. The truth lies somewhere else. Here is my attempt to normalize the engines of the era and rate them relative to one another: Since the published numbers were a little arbitrary I think all we are saying is that 70 SR or SF from a Riv, an Electa, a LeSabre 455, a non Stage GS and an Estate Wagon are the same engines. I know JW says that based on his dyno results few, if any, will meet the 510 ft lbs rating. Studaker recently implied a finger may have been on the scale when they were rated for torque plus they were using dials back then. The factory stage 1, 70 SS made 376 hp at the specified rpm (around 5000-5300) and I do not recall the exact #) So if you think the 70 Electra small valve engine will make the 370 hp rating at the same rpm stock some might say that is too optimistic. Here is my attempt to mathatically calculate true various Buick engine outputs from the known 376 hp of a 70 stage one SS engine. Regarding the 430 at 10.25 to 1 versus the 71 455 at 8.5 to 1 relative outputs. Let's take the small valve 70 455 at 10.25 to 1 as our normal at 350 hp. I realize the factory compression ratios were overstated but for this mental gymnastic the same error should be true for both engines and so it should make little difference in the outcome. Assume that although the curve is not linear the drop in the 455 compression from 10.25 to 8.5 is 1.75 points. Futher assume that on this part of the horsepower vs. compression ratio graph you lose 4% for every point of compression. ( Correct me if this is not the rule of thumb except for higher compressions) So the 71 455 relative to the smalll valve 70 is 350 hp gross -7% = 325.5 hp Now the 69 430 has the 10.25 compression just like our 70 455 normal but it has only 430 cid versus 455 ( rounded). 430/455 = 94.5% of the cubes 94.5% x 350hp ( the 70 455 normal) = 330.76 hp So all other things being equal like valve train efficiency the 69 430 cid makes 330.76 hp while the 71 455 makes 325.5 hp ( both gross). Now lets go a step further. I believe Dennis Manner told us at the Flint 100th that the large valve 455 makes about 15 more hp than the small valve. So on this relative scale ( not the 376 hp scale ) the 70 455 large valve ( stage 1 engine would be 350 plus 15 hp = 365hp So their relative outputs on these assumptions would be 70 455 stage 1 -----365 hp 70 455 small valve --350 hp 69 430--------------330.76 hp 71 455--------------325.5 hp So you want the top scale stage 455 to be 376 hp to make everything relative to a known 376 hp dyno value? Add 3% to each number. 376 hp ---70 455 stage 1 360.5 hp---70 455 non stage 340.68 hp --69 430 cid 335.26 hp ---71 455 cid 316.92 hp ---69 gs 400 cid All are in gross horsepower not SAE. Deduct 20% to go to SAE [Since originally posting these calculations we now know from something Joe Taubitz posted from D Manner some accessories may have been used by Buick in 70 so 20% may or may not be correct.] Where would nailheads fall in this relative scale? Since the nailhead heads are much less efficient and the displacement is less than the 430, I think it is a safe assumption that they would be less than the 430 cid. But I have never seen any dyno results to verify this. Except for the nailhead comments, these are just the math results derived from the 376 hp and 15 hp spread data points supplied by Dennis Manner. So you can see from this little math exercise that relative to the factory published horsepower ratings some engines were understated and some were likely overstated. So your Riv engine is around 360 horsepower gross on the foregoing scale. But remember this is just a peak reading for a given and sometimes arbitrary rpm. What really counts is the surface area defined by the torque horsepower curve over a given rpm range, the power to weight ratio for a given vehicle, gearing and traction set up.
