The Ford Barn

PGBuick · 04-10-2023, 08:03 AM

I have a pretty stock '48 flathead and not looking to maximize HP or performance. It's sitting in my '36 chassis with a vega steering box and cross steer setup with stock wishbones. I found a set of cast iron exhaust manifolds that I can make work for a true dual exhaust. I also found a set of headers from Flowtech (12701-7FLT) that will fit around the steering box and dipstick with slight massaging.
The headers have 1.5" diameter tubes, which are much bigger than the 1 3/8" exhaust ports in the block. What is the consensus from the flathead wisdom chiefs on exhaust flow, issues, problems, prior experience, etc, in choosing what to go with?
Thanks in advance for your shared knowledge.

04-10-2023, 08:03 AM	#1
PGBuick Senior Member Join Date: Nov 2021 Location: Central Mass. Posts: 100	59AB - Headers vs stock exhaust manifolds? I have a pretty stock '48 flathead and not looking to maximize HP or performance. It's sitting in my '36 chassis with a vega steering box and cross steer setup with stock wishbones. I found a set of cast iron exhaust manifolds that I can make work for a true dual exhaust. I also found a set of headers from Flowtech (12701-7FLT) that will fit around the steering box and dipstick with slight massaging. The headers have 1.5" diameter tubes, which are much bigger than the 1 3/8" exhaust ports in the block. What is the consensus from the flathead wisdom chiefs on exhaust flow, issues, problems, prior experience, etc, in choosing what to go with? Thanks in advance for your shared knowledge.