WydGlydJim

I wondered what the '73 is rated at in gross horsepower terms. The car runs very strong, and it shifts really hard. I'm used to running a 12 flat car, so I was surprised at how well this car runs, since it is rated at a mere 275 ponies.
:chevy

jrzvette

A general rule of thumb is a loss of 20%. So your 275hp would work out to about 345 gross.

Tom73

The '73 LS4 is very close to the earlier 390 hp LS5 but with lower compression. In fact the 73 LS4 has 5 more hp then the 72 LS5 :).

tom...

WydGlydJim

Thanks guys! Like I said, I was pleasantly surprised. Haven't had the car that long!
:cool:

Clink69

Rule of thumb is weak here... This all depends on what options and exhaust you are running on the car. Basically what is dragging on the engine. For mine , my loss is only 7 or 8 % since I have almost open headers and NO options. Fan, waterpump and alternator. So it depends on a lot. If you are running AC belt, power sterring , breaks , and mufflers NO headers, etc. it wil go to 20 % or more...

gross is a measurement of engine with Open headers and NO attachements on an engine dyno.

theandies

Try this link. If you don't have the actual 1/4 mile numbers and weight you can guesstimate. There was a topic a day ago that had all the weights listed. I can't remember what a 73 weighed.
http://www.gordon-glasgow.org/hpcalc.html


[Modified by theandies, 8:37 PM 7/16/2003]

73 LS-4

The closest conversion that I have seen posted was with a 71 LT-1 which was gross rated at 330hp and net rated at 275hp. So a 73 LS-4 should be something in the 330 gross range.

:cheers:
Pat Kunz