Curtis,
Don't let them get to you ;-) Some have forgotten manners and that not all are 'old boys' who know the in's and out's, a long solid knowledge base of these trucks.
Welcome and I hope you will stay as there are many who have the knowledge and are kindly willing to share and guide.
I do understand the sentiment expressed about pulling out the 270 engine and I am sure we can convince you of it's attributes and reliability. As well as help you make this truck into something that will fit your needs. There are options to help with speed

I live in Colorado and have a 1951 GMC 5Window with a 270 in it. I love it! If it ever DID (just wanted to make sure the DID, was clear) truly break down, I would rather be driving it than my 1998 Toyota corolla. I would be much more confidant of the ability to get it running again quickly.
Again, I do hope you will stay.
5WindowGirl