Kernel 4.x

Hello, I have an old Dell E521 (circa 2007) computer that I took out of storage. It has an nvidia geforce 8400 video card. I installed opensuse Leap 15.2 KDE, but the G03 driver isn't available for the stock 5.3 kernel. It's using the nouveau driver but that causes some weird screen blanking (even with XRenderer), random screen corruption and system freezes. I have used opensuse on it 10.0-11.3. Been so long I forget, but it has always been suse/opensuse. Is there a repo that I can use to downgrade the kernel to 4.3 (or any 4.x) that I can use with 15.2? I know it's a weird question, but I figure the machine is so old that it wouldn't benefit from any kernel after 4.x any way. Thanks. Alvin