I am thinking of using the H&H C4 adapter on an upcoming build. As far as my research shows this is the only adapter that works with the earlier blocks. Is there another option? Any comments good of bad? Thanks.
Have you read this thread? Technical - Transmission horsepower losses | The H.A.M.B. I have never driven a stock flathead with a C4 or any automatic for that matter, but it seems if the facts are correct as stated in the thread, you may lose half of your horses. You might consider a performance upgrade in addition to the automatic. Just a thought.
Yeah I read some of that. I even posted tech info there. I currently have 3 not flathead vehicles with C4 autos. Ford 170, 200 & 289. C4 is the least parasitic auto transmission. Better to be auto than not drive at all. I have been running C4’s for years and yes they loose a bit of HP but most of the bad stories are from using an inappropriately high stall converter.
None of this is helping with my original question. Just for the record I just drove to work in my o/t 3400 pound truck with a 2.8L straight six ford and a properly setup C4. Keeps up with modern cars aka will do the speed limit (55 at2300rpm) it won’t win any races and I don’t push it hard just cruise around. So you all believe a v8 with 20 more horsepower than what I drive now in a much lighter vehicle will lose so much horsepower that it will go backwards?
Not sure I can answer your question, as I haven't researched flathead adaptors in many moons. I still have a C4/AOD to late model flathead adaptor on the shelf from Speedway. Maybe some day.... Anecdotally, a buddy of mine ran a C4 behind the flatty that I re-built for him in a '48 Business Coupe for many years. It worked great and preformed well. The engine was a very basic Hot Rod Flathead build. Offy 2x2 intake and carbs, Isky cam, MSD distributor, Edelbrock Heads, and Red's Headers. It was geared to cruise at 60 mph at about 2200 rpms. I drove the car a number of times, it always impressed me how well that combination worked. I don't remember what adaptor was used, it was originally put together with the C4 in the 90's.
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