Hi Scott, I could only find the product dimensions which are 7.5 x 5.6 x 4.9 inches. The size of the circumference is not mentioned anymore since fitment selection is guaranteed by simply selecting the correct (complete) year, make model, submodel, and engine size of your vehicle. Please also double-check Your Vehicle Fit Details as well as the Vehicle Fitment Information table on the product page.

3 inch

Hi Scott, That detail is not mentioned anymore since fitment selection is guaranteed by simply selecting the correct (complete) year, make model, submodel, and engine size of your vehicle. Type the part's name in the search box. Once your application is selected, you’ll see a “Guaranteed to Fit” badge if the part will fit, and we recommend that you also double-check Your Vehicle Fit Details as well as the Vehicle Fitment Information table on the product page.

It is 3 inch

Hi, Unfortunately, this one only comes as an assembly.

Like Amel E. said. One part. I bought one and it did not solve my problem. My problem was surging , bucking engine at stop lights, etc. and trying to stall. Disconnecting the Mass Airflow sensor pretty much stopped the problem; but engine was a little rough but acceptable. A mechanic found a vacuum hose leak somewhere. Fixed that and engine was a LITTLE better with the Mass Air Flow connected. So, I have had it disconnected for months. Have another problem now that I think might be an old stretched fan belt. Was showing the problem to a friend and he asked to see what happened when i reconnected the MAS. Wonder of wonders, NOTHING much happened! Like it was working. By a day later, the Check Engine light (which was on because of the MAS being disconnected) went away. So, whatever the MAS issue was seems to have gone away. BTW, I replaced two other sensors related to the surging/stalling and removed and cleaned another sensor thing - which did nothing. My car is a 2000 Chevy 1500 van.

Hi William, I'm pleased to assist you. Yes, this sensor is compatible with the 1998 Chevrolet K3500 Silverado 8 Cyl 7.4L. Use the link below to directly place your order while the part is in stock. I hope this helps, and enjoy shopping! https://www.carparts.com/mass-air-flow-sensor/drivewire/repc316705?can=CPGG4850_CSQA_20231218

Hi Thomas, I'm glad to help you out. Our products are sourced globally from only OES (Original Equipment Suppliers) that comply with QS 9000 / ISO 9000 / ISO 14000-1 / TS16949 standards. A majority of these suppliers are located in Taiwan. You can use this link to go back to the item page and continue ordering the part at 56% off the regular price today: https://www.carparts.com/mass-air-flow-sensor/drivewire/repc316705?can=CPAP3648_CSQA_20221009 I hope this helps. Happy shopping.