Compression ratio dropped for '71. Horsepower rating system changed for '72. Some "real" loss of power, mostly "phony" loss of power due to the rating change.
I am looking at this car. https://www.coyoteclassics.com/vehi...w8S3SU44JbpzLynswdvsXtBuuY5rSETroD8fbPdo-uLcs
Yeah folks see the "net" hp rating and think they must be slugs. Funny enough the net HP is a load of crap... every other damn dyno test is gross expect for the chassis dyno..
Looks like a decent car if it checks out in-person. On paper, the 70 had 2 points more compression. In practice is was likely 70 had 9.5-ish compression ratio and the 72 had 8.2-ish compression ratio. You can run regular fuel in it if it hasn't been modified. The 72 Stage 1 was on par with the 71 Stage 1 since the only thing they changed was from gross to net. The engines were identical where it counts. Unless you are going to race it, I wouldn't worry about it. A 70 is likely more desirable but the 72 should be a good solid car, too.
I've always heard 1/10th of a second is a car length in a 1/4 mile pass, so 1/2 a second is more like 5 car lengths?
100 mph is 146 feet per second.. a tenth would be 14.6' at that speed, which is not even front to rear bumper..
10hp is roughly a 1 tenth...hard to remember what the car length correlation is ha...it may be that many cars
Actually, no. At 100 MPH a car travels about 15 ft. in 1/10 of a second which is about a car length. So, in .5 seconds there's about 5 car lengths difference.
Was mentioned in a old article that the 1969 400 Stage 1 with 3:64 gears was about 4 car lengths ahead in the 1/4 compared to the standard 400 with 2:93's. So a 400 Stage 1 runs a 14,40 off the showroom to a standard 400 14.7 or 14.8 So the .1 difference is about 1 cars length.
what the 72 lacks in static compression can almost be bought back with cam timing and an increase in dynamic compression. I did this on my low comp motor and it worked well, put it into the 12's with just headers and performer intake. Rest of the block was stock '72. Got the cam from Jim and he degreed it and told me where to install it at.. it wasnt a radical cam maybe 230/240 and it was ridiculously retarded but it worked.
I ran a stock 72 for a bit in a 70 skylark it was stout for a stocker....ran really well...way better than a 70 GS 455 we had few years prior...theys good ones and bad ones
