360 LA turbo exhaust question

I keep coming across these $450 things...
DODGE MOPAR Twin Turbo Manifolds Headers T3 T4 318 340 360 LA 5.2L 5.9L MAGNUM | eBay

hard to spend $450 when you can buy the same thing for $160 and wend different flanges on. you can literlly buy a set of LA SB ebay shorties, and these ebay SBC headers and make a set for under half the price of the mopar ones.
EXHAUST HEADER FOR 65-89 CHEVY SBC 4.6-6.6 V8 T3 RACING PERFORMANCE TWIN TURBO | eBay

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