I'm getting ready to drop the engine and tranny in next weekend. After that I have to hook my wire harness up and a few other odds and ends. I want to go ahead and fire her up to set the initial timing and maybe tune a decent idle. Here's the catch. After the Hooker LT's there's NOTHING. No cat, pipes or muffler. I have my earmufs I use for shooting but will they be enough? I imagine they would but wanted to hear if anyone's done this.

 

yes it will be loud as hell. its like a thundering vibrating sound, throw some turndowns on the ends of the headers and it at least keeps the noise out of the pass. compartment a little bit, but its still damn loud.

 

It will be loud yes. If you're worried about it just wear your earmuffs. I've been in a closed dyno garage with my old LT1 with straight pipes, winding it up WOT to 6k on a dyno run. I didn't wear earplugs and I'm fine.

 

Will it be measurably loud.. certainly.
Will it be loud personally.. depends on ones definition of 'loud'

If you define loud and requiring ear protection by OSHA, you need earplugs to use the telephone.

Ask an older fabricator... pffht.. 'i've heard much worse noise'

Headphones will be pleanty to keep your ears safe.
I've been in places that require headphones and earplugs and you can still hear the noise drilling through your skull (and body).

Even after the multiple years of torture I've put my ears through.. my hearing is -3db in only a few frequencies as deemed by d.o.t. testing. Although the mild tinnitus is annoying once in awhile.

The short amount of time you'll be listening to the noise.. wear the phones and worry not.

Just my opinoin though...