also got these heads with the cylinders, they do fit on the 3 5/8 cylinders but they are already ported, someone did a shitty job, the valve guide literally just fell out when i pulled the valve and it looks like a head gasket blew. So i wouldnt feel good running these, the heads that came on my motor are in much better condition. These would need alot more work and id rather buy std or sorenson performance heads, unless it was way cheaper to fix these. Im not looking to have a drag bike.