Questions.

Which one would go a lot faster if I modified it, the Ford Lightning or the Chevrolet Silverado SS?

That's going to depend on the specific mods and whether you're referring to top speed or acceleration. As always, observe all traffic laws, drive safely, wear a seat belt and have fun.

Have you looked into dodge?

No.

Srt 10

According to the specs the lightning and srt-10 are pretty close acc and top speed. I think that the srt-10 would win personally. I have raced a few lightnings with my indy and was not impressed with them, not much fight.

SRT-10 now has the world speed record for a Pick up truck, took the record from the Lightning 2 months ago. Although the SRT-10 is $20k more expensive than the Lighting and only took the record by 7mph to the Lightning. In a race they will be pretty evenly matched.

Standing qtr they are both reasonably evenly matched at around the mid 13's time up the strip.

The SRT-10 has more power and more torque than the Lightning (500/500 compared to 380/450) but for an extra $20k its not impressive speed wise, accleration is within .3secs of the Lightning 0-60 and maybe half a sec on the qtr.

If you want to put $5k or so into a Lightning you'll be getting the low 12's or high 11's on the qtr and still have a reliable daily driver.

I have raced a few lightnings with my indy and was not impressed with them, not much fight.

Whats your ride??
A stock L will beat pretty much everything and held the world speed record for a pick-up for 5 years

Unfortunately, the SS is all wheel drive and an extended cab, giving it a ton more weight then the Lightning and the SRT-10. :( tsk tsk to GM