GM injector 24508208 which are used on GM's Gran Am C5,
The SC3800 or Grand National Buick SC'd cars and are like 42 lbs in a C5 or 36 lb/hr in older cars using 43 PSI fuel rail pressure

They are Bosch Multech-II design. 12 Ohms - high impedence

LS1 fuel injector (98) = 12533952
LS1 fuel injector (99-00) = 12456154
LS1/LS6 fuel injector (01) = 12482704
LS1/LS6 fuel injector (02-04, at 28#; used in Corvette Z06) = 12561462
LS1/LS6 fuel injector from C5R racecar (42# at LS1/LS6 58psi pressure) = 24508208

Should these injector considered for Magnuson LS1 Motors?
Are they similar to the GNX Buick Injectors?

Yes they are the same as used in the G.N.

I have used them on my 1999 C5 for over 4 years.

Here is indepth analyzing the effects of injectors as to voltage they receive and effects of internal coil reactions and duty cycles.
The 42 lb/hr injectors used on our C5 were used for this testing

Effects of Injectors

Calculating the flow of injectors when the fuel rail pressure is different
Injector flow as to fuelrail pressure

Since these injectors were in my 1999 C5 since 2001 I took them out to see how they have stood up all this time and they were just fine.
Nozzle holes were clean and it looked like the filters inside were also OK.