S Code 390 - practical power increase if keeping stock heads / exhaust

[Joe-JDC]

If your engine is truly a 57K mileage and never been into, then you should definitely think about changing the camshaft timing gears and chain.  You can still find C6AE-9425-H aluminum intakes and C7AE-F intakes with the thermactor tubing holes and remove about 50# from the engine.  735 cfm Holley and FPA headers, and 2 1/2" exhausts and call it good for the street.  Joe-JDC

[cheeser]

Joe,

I’ll look out for C7AE-9425-F intake if I can find one for a reasonable price.  They appear to be similar with PCV balance tube hookups as the S code intake, but tube is slightly different.

[gregb]

For me, if it was that original I wouldn't mess with it, especially if you are going to get into it in a couple years.  I'd get the carb and timing dialed in, and I'd put a decent exhaust on it, meaning some larger pipes and mufflers of your liking, with the stock exhaust manifolds.  You want it to feel more responsive put some 3.50 gears in the back and call it good until a time you want to really dig into the motor. 

[cheeser]

For me, if it was that original I wouldn't mess with it, especially if you are going to get into it in a couple years.  I'd get the carb and timing dialed in….

That was my thought for now regarding carb and timing…just getting it dialed in for now.  I may send the carb out to Air Fuel Spark for a quality rebuild, and distributor our for recurve.

I’m just gathering ideas in the event I want or need to do a quality rebuild in 1-2 yrs, and start gathering some parts.

[frnkeore]

Some food for thought:

Since the engine isn't installed. I'd keep the basic long block, as is, with the exception of replacing the cam. Since your considering the CJ heads, you shouldn't be  concern about the head cast # so, by that you can get a set of C6 - R heads and let Blair work his porting magic on them (~300 cfm) go with the C7 - F intake, CJ ex manifolds 2 1/2 pipes, +/- 735 cfm carb.

I think that might get you the most bang for the buck.

I dislike cast iron manifolds, even the CJ and weighs more than most all FE intakes by about 10 lb.

[cheeser]

Since the engine isn't installed. I'd keep the basic long block, as is, with the exception of replacing the cam. Since your considering the CJ heads, you shouldn't be  concern about the head cast # so, by that you can get a set of C6 - R heads and let Blair work his porting magic on them (~300 cfm) go with the C7 - F intake, CJ ex manifolds 2 1/2 pipes, +/- 735 cfm carb.

I think that might get you the most bang for the buck.

I dislike cast iron manifolds, even the CJ and weighs more than most all FE intakes by about 10 lb.

I'm going to drive the car over the summer to see how it performs, but will have the distributor recurved as that's fairly simple.  As noted earlier, this isn't for max performance, but good reliability with some bump in power.  As I want to keep the thermactor system (for originality), that leaves me with the stock GT390 or CJ heads (from my understanding).

I'm a year out from going through an engine refresh, which gives me time to start looking for parts.  It appears to be a challenge in finding from a trusted source...especially the heads.  I have the challenge in finding a respected engine builder as I'm in Colorado, and need to get the engine to them while trying to keep the downtime to over the winter.

Obviously keeping costs in check and "bang for buck" are on my mind, but I understand a quality rebuild with good parts and having it dynoed / broken in will cost...something I'll have to work on with a builder.

For now, I'll start looking at the F427 or PI intake, and maybe the CJ heads.  I'll also have to start looking for a builder at some point to discuss the internals (head porting, cam choice, etc.).

Thanks for the assistance / advice from the group. 

[Rory428]

If your engine is truly a 57K mileage and never been into, then you should definitely think about changing the camshaft timing gears and chain.  You can still find C6AE-9425-H aluminum intakes and C7AE-F intakes with the thermactor tubing holes and remove about 50# from the engine.  735 cfm Holley and FPA headers, and 2 1/2" exhausts and call it good for the street.  Joe-JDC

I absolutely agree with Joe on replacing the stock nylon camshaft timing gear, if it is still in there. Same with the valve stem oil seals. I have pulled down quite a few "untouched" Ford engines, that had an abundance of fragmented nylon timing gear teeth, and disintegrated valve stem seals in the bottom of the oil pan. And for whatever reason, Ford chose to put a round hole in the screen of the oil pump pickup tube, which is more than adequate to allow small pieces of cam teeth/valve stem seals to find there way into the oil pump, which will jam up the oil pump gears, which then lock up, and twist up the oil pump drive rod, like a barber pole, until it snaps. The engine keeps running, but with no oil pressure, and even if you catch it as soon as the oil pressure gauge drops, or the idiot light comes on, and the lifters start ticking, there is a very good chance that you won`t be able to shut the engine off before the crankshaft bearings get destroyed.. I lost a very good running , low mile 302 in my 79 Mercury Zephyr Z7 that I bought from the 94 year old original owner about 10 years ago. I was cruising down the freeway, and suddenly the oil light came on, so I shut off the engine right away, and coasted to the side of the highway.  I checked the oil level first, which was fine, but when I tried to crank the engine over, it was already stuck. I sure wish that I would have changed the timing chain set and valve seals before hand.

[MeanGene]

Yep, have to agree on the timing set and seals, the teeth will sooner or later get shucked off, and the seals will be just as brittle. Really not that hard to replace the seals with the heads on, if you have the right tool. And I have seen a cherry CJ get boogered by a little chunk going thru that screen into the pump and locking it up, barber-poled the drive and boom