I'm open to swapping better aluminum heads and installing the CJ style headers if it was as simple as replacing parts.   From my understanding, it isn't that simple as I would then have to work other issues like pushrod length and other measurements...areas where I'm not skilled / lack experience.  My main reason for sticking with the C8AE-H heads is I (in theory) wouldn't have to worry about those things...but probably not cost effective by the time I paid a shop to port.

As I mentioned earlier, I'm hesitant doing headers now with the current GT style heads, and then have to pay for another CJ set later on if I go with better build using aluminum heads.  If I was never going to install better heads in the future, then it wouldnt matter, but want to leave the option open for now.

Members here have already hit the nail on the head...I have to figure out what I want.  This is probably a common problem where folks with these cars are going to be primarily cruisers with an occasional throttle blast...we all want as much HP as we can, but would probably live with a more modest build (425-450 hp) which is still respectable.

frnkeore pointed out the slippery slope perspective in opening up the engine which I'm trying to avoid to some degree.   If I went with pulling the heads, then Id probably prefer to do this once and put on a good set.

Thanks...I appreciate the constructive feedback.   Looking forward to tackling the things I can do myself, but see myself working up towards a modest quality build in the future.

Quote from: My427stang on August 21, 2021, 09:30:00 AM

I think headers are beneficial and should be done during the intake swap for a couple of reasons

1 - Pull the heads and replace valve seals.  With some smart shopping you can put a viton seal on the stock guide.
2 - You can fix any broken bolt easily and make sure exhaust flanges and gaskets match on the bench
3 - You can likely set the headers in before the heads
4 - The headers will make the other parts work significantly better

Then once the heads are back on, finish the intake install.

Of course you could ignore the manifolds, but if you go to do it later, I'd expect you'd have to do it all over, and/or pull the engine.

On a '68 Cougar if I had to pull the heads I think I'd pull the engine. Not saying cannot be done in the car, but is a bit of a PITA! Of course swapping intakes is n fun either.  the factory shop manual tells you to use a hoist to lift the intake manifold which I can understand as it is what 80 lbs?  Headers are best, but if he is not looking to get into a whole rebuild/remake project and it is running good, just swap the intake/carb. The CJ manifold are not as good as headers, but are decent and headers can be a pain. OP has not stated a goal so guess just wants a bit better performance.

At this time, I have two goals....near term and long term:

- Near term - Some are purely aesthetics I wanted to dress it up a little with an aluminum intake (cars and coffee, etc.), while also dropping a bit of weight from the front end.  I also wanted to bump the power a bit to give it a bit more acceleration when wanted.  The Denver altitude has already taken some of that power away, and would like to address that.  The car is primarily just used for fun at this time...haven't really had a chance to drive it too much due to work and such.  Since the engine runs well, I'm trying to see if the intake/carb/distributor, and maybe headers is simply enough at this stage.  The car has 2.73s at this time...was thinking of going to 3.25 as I want to still drive it on the interstate out here....70-75 mph seems to be the min sustained speed I need and didn't want the revs too high on those drives.

- Long term - That depends on how the other efforts work out and if I'm satisfied with the power level for simply driving around in town / interstate, and the yearly blast down the dragstrip.  I'm not expecting a competitive drag car, but would like one that is respectable...low 13's here in Denver.  My427stang has provided me advice for some of this.  I would love to jump on a mild 445 with 500+ HP, but as the engine runs well and the associated costs hold me back at that.  However, if the engine was to take a dump, I would like to do more than a simple rebuild as I only want to do it once.

My current storage / working environment for this Cougar is fairly limited at this stage, so I don't really want to do anything where the car is blown apart for more than a week or two.  This is another reason I'm keeping the current changes somewhat small.  If I ever had to pull the engine, I would have to find one of the DIY garages around here...can't do it at my house as I have the normal family cars to keep in the garage...damn Denver hail.

I am fairly good in being able to remove/install stuff, but would probably rely on an engine shop for heads and engine mods. 

I came from a 2013 Mustang GT with TVS style supercharger....609 RWHP.   That car was extremely fun to drive, but I'm not expecting that level of performance.  I had to make the adjustment in how the cars drive.

If I was to install headers, I was hoping to have enough room by jacking up the engine via the oil pan....I recognize pulling the engine / heads may be the best option though.  I am a but concerned if I buy the headers with the CJ flanges (assuming my heads have been modified - will check to see if all bolts are in) only to find out they don't seal well on the lower port.  Isn't the only true fix a new set of heads with the right configuration as I can't go back back to a regular 390 header (assuming my heads are modified)?

I was tempted to buy a new set of heads and cam and install while in the car, but have read somewhere that the heads should be gone through and rechecked.  If that was the case, then I was probably back to letting a professional go through it and doing it correctly the first time.

So I seem to be in a catch 22...going ahead with the just the intake/carb/distributor or just leave it alone (as engine runs well) and save up the funds to perform a decent upgrade that involves pulling the motor.

Thanks for the info. 

Car currently has a 2.25” dual exhaust and 428CJ exhaust manifolds from the original owner during an engine refresh back in 2008.

@My427stang…now considering the header change based on what you’ve mentioned before.  I have to checkout the existing manifolds to see if the heads were modified to accept all of the CJ exhausts bolts, or if they simply left a few bolts out.  I need to double check the existing head casting numbers to see if the are the C8AE-H heads (which I believe would be stock) or if they were swapped as well with true CJ heads.  If I’m able go big down the road with a nice build, I only want to buy headers once…assume ones with the CJ pattern.

I purchased a Blue Thunder 427 MR 4V intake shortly after purchasing a 68 Cougar with stock 390 2V motor…X code @ 10.5CR.  I haven’t installed it yet as I’m a bit paranoid installing it correctly with out vacuum/oil leaks.  Every project seems to take longer than expected, although it appears to be fairly simple when taking time and checking fit…bit harder looking at rear while in car.  I already have an old Holley #80457 600 CFM carb I was planning on using after I rebuild it, but open to purchasing a new carb.

I’m curious in what I could expect from a power bump in this configuration…30-35?

Update: this was an original family owner California 68 Cougar XR-7 car for 52 years with approx 114k miles.  I purchased it last year, and want to keep it stock appearing where possible.

I’m curious in what you find.

I’m having a similar problem where my 390 dies after getting hot…after a 10 mile drive, just seemed to die quickly after a few sputters while on highway.  Mine starts back up after 30 seconds or so after 5 sec or so of cranking.  I thought mine may be a venting problem as well (seemed to be a vacuum in tank after removing cap), although I noticed I had fuel in fuel bowl via clear bowl window on my newer Holley 2 barrel.

 I went ahead and replaced with a new G40 stant cap from eBay, and replaced existing Pertronix setup with new igniter II and Flamethrower II coil.  Ran fine after a quick 5 mile test..trying this weekend for a longer highway run.

Ok, it appears I can make decent power with a stroked motor and good heads, with slight hit do to the CJ heads.  I believe my CJ manifolds are reproductions and thought about extrude honing as well...noticed there seemed to be minimal benefits, especially for the cost.

This combo of a stroker with nice heads and 428 CJ exhausts would be interesting to see on a dyno.

So I haven’t heard anyone saying I’m nuts so far :-).  With the stroker kits and nice heads out there now, I assumed decent power could be obtained, while keeping an outwardly stockish appearance.

My last adventure with an FE engine was in High School in the 80.  I had a 64 Galaxy with 4 spd and blown 390.  I found a wrecked 62 Galaxie with a freshened 406 tripower.  My auto shop teacher let me transplant the 406 into my 64...had a lot of fun, but it rusted out being WI and I left to join the military.  I sold the motor about 15 years ago as I thought I’d never have another FE, but here I am again.  I had a blown Coyote in my 13 Mustang w 609 hp for a few years...extremely fun and smooth, but sold it for the Cougar.

The existing 390 runs decent now, but it has the stock 2 barrel.  Until I can convince the spouse on this, I was going to put a Blue Thunder 427MR intake on and 4 barrel in the interim...later this summer once I work the rest of the Cougar gremlins out.

I have been watching Barry and Lykins, and this forum just to see what is out there.  I am not aware of any knowledgeable FE builders in the Denver area, thus another reason for me to stalk this forum.