is the 5.7l engine in a 97 1500 a ls based engine or a lt based engine, i guess what i am asking is if ls1 parts will bolt on?

 

I'm not 100% sure but I think its more of the lt1 type...

 

0 ls1 parts will bolt on to that engine. None of the internals or accessories are the same. Beginning with the 99 model trucks (NBS of course) they started using the LSx style engines. The engine in your truck is pretty much a derivative of the old trusty SBC that's been around forever.

 

Yep, retsell is exactly right. Your 97 is LT1 based and has nothing in common with the LSx construction.
For those with 99 models, retsell is also correct that the NBS ( new body style ) is the LSx configuration. You could get either model that year so be careful!

 

it's not a lt1 based engine. the lt1's have reversed cooled heads. as retsell said their petty much the same old SBC engines with a vortec heads and intake. also with fuel injection.