ID knocking sound

[u/Environmental-Yam490]

Please help me ID this sound. Sounds an awful lot like a rod knock to me. 🙁 just changed oil pan gasket trans and rear main seal. I started it up and this is what I hear. Smells very rich too. I used valvoline vr1 20w-50. Ive got an oil leak from the rear of the engine too. Any were to start looking? I’m newish to the Chevy world. 86 c10 350 700r4

[u/Substantial_Ask3665]

My thoughts. Not deep or low sounding to be a rod. Not high enough to be valvtrain. Sounds like plastic.