SD 389 build has finally begun....
Well, the divorce is now final and life begins again. I've pulled out all the components I've been accumulating for the past couple of years and have decided to do something a bit different. As the cost of building a true SD 421is outside my budget, I've decided to take a step back and build an authentic recreation of an early Super Duty motor, the SD 389. My original plan was to put a blower on this motor, but I decided to back off that direction and stay with a traditional high compression set up. The block is at the machine shop for cleaning and baking, the heads have been disassembled. And I have my first two problems that I need input from the group. These are 306 heads.
Attached are pictures of the combustion chambers showing the most and the least damage caused by sitting water. I have been told (and I don't know if it is true or not) that there is enough room in these heads only for either an intake or an exhaust seat, but not both. Can anyone either confirm or dispute that statement. I would like some input on how to correct this problem, including where to send these heads for machine work.
Problem 2 is the pinned in studs. The shop were I took these to be cleaned and magafluxed had no idea how to pull these studs out. So I told them to do nothing with them. My original thought was to remove these studs and substitute an contemporary screw in stud. What are the thoughts here? My plan is to use the McKellar #8 cam I have but to substitute new valves, springs, lifters, retainers and rocker arms. I have an original set of NOS pushrods I want to use here.
Next question.....can I get some input on which manifold to use. I read John from The Carburetor Shop's article on tripower and a V-8 engine and came away from that with the notion that if you want a set up to go fast you use a single four-barrell or a dual four-barrel setup. Well, a dual four-barrel was not available in 1961, so that is not a choice for me.
Here are some of the specific parts to be used on the build:
1961 4-bolt Trophy Block at standard bore, new studs to replace all bolts
1961 540306 heads
1961 SD manifold (based on input from the group)
1961 SD389 distributor
NOS McKellar #8 camshaft
Ram Air V 3.75" stroke crank. The crankshaft is currently on its way to Henry Velasco to be reconditioned back to factory specifications. Henry's shop did the original machine work on this crank. I had the crank X-rayed before I sent it to California and it checked out ok. The picture is the way it looked when it came to me from RacingJunk.
NOS Ram Air V or SD-455 rods
I have a 1961 era set of NOS forged AL pistons. What is everyone's thoughts of using these for this build?
Also, the heads for this build came off a 1958 Pontiac that was used for dirt track racing in South Carolina. The guy had them set up for reverse flow cooling. I have all the components needed to duplicate the reverse flow set up. I know it is not bone stock, but I'm not really that concerned with having something the way it came from the factory. I only want it to be period correct. So if this would have been a modification that would have been done back in the day, it's open for inclusion here. What are everyone's thoughts on reverse flow cooling?
I still need an early SD harmonic balancer. Can anyone help me out here? I know these are not cheap.