A quality steel hood will usually fit with no issues but for me I like the weight savings of a glass hood and you can get into scoop styles that you really can't do in steel.
A glass hood will take more prep to fit and paint but the quality ones are minimal, I have been lucky my first two hoods fit well, the second being a Harwood show series.
My newest hood I had custom made by Glasstek which is a bolt on 6.5" Sunoco style hood which I have yet to fit to my Monte but don't expect any issues.
For my Regal I kept my factory hood but added a 2" fiberglass bolt on scoop to give me the clearance I needed and made it functional.
If you don't need the weight savings a good steel hood will be an easy install, fiberglass hoods typically need to be trimmed on the edges around the perimeter and requires a little more work to get a nice fit.
Availability of the style hood for your particular car will also be a deciding factor.
I have also heard some of the cheaper glass hoods fit like crap and need a ton of prep just to look OK at best.
hello people: and hello 565. What's under the Chevy hood and same with the Buick? On my T the up pipe hits the insulation a bit but it's made a home. I think it started hitting after I put in the SLIC.
I just read the Chevy stuff but a ported SV is a blower?
Had a 4 inch bolt on but didn't like the way it fit it would actually move @ different temps and the sun hitting it. It also took away the sleeper look. There wasn't much weight saving with the one I had. Have a metal one on the Sonoma.
My Harwood is definitely heavier than my new hood and my first hood but when I ordered it years ago it was the only 4" cowl I could find but the "Show Series " has a second smooth layer of fiberglass on the inside which gives it a nice finished look but also it adds weight and takes another 1/4" of clearance away.