65A stiffness up to 300HP please check our other listings for stiffer bushing to handle more power. 

New motor mount break in period is 250-500 miles during break in period you will notice vibrations and noise that is normal for performance Urethane bushing after break in period the vibration will calm down but it will still be stiffer than stock motor mounts. Please keep in mind that this is for Performance motor mount kit. 

NOTE:
It is strongly recommended that all installs be done by a mechanic or automotive specialist.
Mounts CAN NOT be returned or swapped out after they have been bolted down (revealing bolt impressions).
PLEASE MAKE SURE THIS KIT FITS YOUR VEHICLE BEFORE BOLTING THEM IN PLACE.
1320 Engine Mounts are built for performance driving. Although 1320 bushings are made to absorb engine vibration, you may still notice vibration depending on your engine's series and HP. 1320 Mounts removes the dampening oil containers harbored by OEM/Stock mounts. By switching to stiffer mounts without the fluid reduces wheel hop and increases driving response. For minimal engine vibration please choose the 65A stiffness. 75A and 85A is very stiff to handle more power but you will experience more vibration that you might not like if your vehicle is a daily driver. 

WARRANTY: Unless otherwise stated in the listing, we will guarantee the product from free of defect for one full year (12 months) from the date of purchase. The warranty does not cover abuse or damages caused by improper use. Any modification to the product will void the warranty. When a warranty claim occurs, we will choose to repair, exchange, or refund the payment at our discretion.

RETURN: In the case of returning or exchanging the product, you must email us first to obtain a returned merchandise authorization (RMA) number. Customer will be responsible for paying all shipping & associated costs for sending the product back to us. The shipping that we initially charge is not refundable. All returns are subject to a 20% restocking fee and the returned product must be in unused, original condition. We will not take any returns or exchanges after 30 days from the date of sale.