I did mine with fat mat, was fairly simple to do, it has its own adhesive. Remember, when you have the doghouse cover off, to cover all of the surrounding areas that you can reach beyond just the cover, it made a huge difference on sound and heat.
FatMat Hood-Liner 34" x 54" x 3/4" Thick Self-Adhesive Automotive Sound Deadening Hood Liner - Aluminum Face
https://www.amazon.com/dp/B00H6X4V7C..._La5yzbXM1H8NV