When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I recently started a thread, "Looking for a 400 Crank". I am going to build a 400 short block from scratch.
Well... I found a crank freshly machined 20/20. I paid $400, the machine shop also has a stack of M blocks a few of which are standard bore and built after late 77. They are ready to be machined for the customer. So I have the crank, block and rods for my build. I have the cam and intake ready to go. It is a Comp Cam XE262H-10 flat tappet. and the intake is a Weiand 8010 made in USA, NOT Chinese. I also have a Holley 650 vacuum secondary carb to rebuild. I will be using Tim Meyers pistons. .020, but may have to wait for them to be stocked. Does anyone here have a set they want to sell? I will use stock heads I may get lucky and find early 400 heads minus thermactor humps. Time will tell.
I hope I can get this built for around 2500 and no more than 3000. Going to be close.
The 61 F100 I purchased is swapped to a 78 Bronco chassis and supposedly had a 400, but sadly it was a 351M. Now I am off to the races.
Glad you were able to find a nice 400 crank. I've got a customer right now who's looking for one. I have a couple of 351M but no 400's. Actually I'm amazed that Scat or Eagle doesn't make a new stock replacement crank. Maybe someday.
I don't think that any 400 heads had much of a thermactor bump. The later ones after about 1975 were filled in around the guide boss but you'd have to flow test it to see if that really makes any difference. The intake port is the problem anyway on those heads.
My 351M engine has the D5-A2A heads, 74.5 cc's and those are plentiful. My 400 will be used mainly for cruising and occasional 4x excursions and camping. I wont require lots of HP since it's a low rpm stump puller engine. However, I wouldn't mind a better flowing head either. I have found 1 cyl head in town D1AE-A1C, for cheap. now looking for it's long lost twin. If I end up using the D5 heads then I would port match and let it run.
I don't think that it is possible to port the D5 to match the D1. On the D5 the port is filled in in the bowl down around the guide. This was probably done to keep the valve stem cooler. I should flow test a D5 to see if there is any real difference.
I doubt that hunting for a set of early heads is worth the effort. They all have the same intake port so minor differences in the exhaust side flow won't make any real difference in power.
Yup, the more research I do the more the A2A heads look like the best choice for my build. Reliability and cost is my biggest concern. Thanks for your input. I will post updates and pics with my progress.
I looked on my computer after I got to the shop and I have a flow test of a D1AE head. It has new SI stainless valves and a fresh valve job but is otherwise stock:
Looking at the flow numbers it's pretty clear where the work needs to be done. This is with a 2.040 intake valve diameter. To put the intake port numbers into perspective check out what a Chevy Vortec head does with a 1.94 intake valve. this was a brand new out of the box head with a stock valve and no port work. Typically they flow about 230 @ .500 but this one was about the best that I've ever seen.
Having the port filled in around the guide boss does hurt flow pretty much across the board from about 200 lift on up. The port never backs up or anything really bad and it still flows enough to easily keep up with the intake port.
Today I went to the machine shop and checked the progress of the work, block is bored .028 and will be finish honed when the pistons arrive. The block was checked for square and decked. Cam bearings installed. They have a fresh set of D1AE heads they put aside for me. I will bring the correct valve springs for the XE262 cam. Looking good so far.
Rezvani's Latest Post-Apocalytic Monster Is a Ford F-150 Raptor Underneath
Slideshow: Called the Fortress, the 850-horsepower pickup combines Raptor underpinnings with military-inspired features, survival equipment, and a starting price of $285,000.
