Stock 5.3L engine into 67C10, SE shorty headers?

[LH Lead-Foot]

Has any one had experience with an LS swap, using speed engineering header of the shorty kind? I have a stock 5.3L donor engine (LS type) from a 03 Tahoe and the $175 budget for my 67 10 pickup is the vehicle getting the engine. There was a few post using long tube in a 67-72 LS swap, but I am using a 700r4 transmission that I bench built and with long tube, many report they have to cut of the "Ears" a little of the tranny and some fitment issue on the driver side frame. I have carefully planning and researching this swap while watching my budget. It has been a unanimous thumbs up for Doug Thorley headers, but I have a house payment. Any suggestions will help because early retirement due to disability after years as an ASE Master, doesn't pay well. Cast iron OEM exhaust manifolds are mentioned using a Camero manifold on the passengers side or a pair. Don't know. The earth should thaw in a few months, so I have some time. Thanks for any input.