In the process of restoring my 1969 eliminator 390. Just recently had the engine gone through and thought I’d share the results as well as review the headers I am using. Here are my build specs:
-1969 390 block (original to car) bored .030 over
-stock heads, mild porting, 428 valves, hardened seats ect
-speed pro h395p hypereutectic pistons
-edelbrock performer rpm intake manifold
-Holley 750 cfm carb
-jba tri y stainless steel headers
-comp cams hydraulic roller cam 33-432-9
282/288 duration, 230/236 at 50, Cam Style:Hydraulic roller tappet
Basic Operating RPM Range:2,200-5,800
Intake Duration at 050 inch Lift:230
Exhaust Duration at 050 inch Lift:236
Duration at 050 inch Lift:230 int./236 exh.
Advertised Intake Duration:282
Advertised Exhaust Duration:288
Advertised Duration:282 int./288 exh.
Intake Valve Lift with Factory Rocker Arm Ratio:0.521 in.
Exhaust Valve Lift with Factory Rocker Arm Ratio:0.532 in.
Valve Lift with Factory Rocker Arm Ratio:0.521 int./0.532 exh.
Lobe Separation (degrees):110
Camshaft Gear Attachment:1-bolt
Computer-Controlled Compatible:No
Grind Number:XR 280HR
Anyways… With that setup it ran with 36 degrees total timing and made 320hp and 380 ft pounds of torque. Peak hp at 5000 rpms. Had a nice torque curve as well. This will be a really nice smooth engine for the street. Ultimately did not make quite the power as I thought it would which is fine. The h395p is a great bang for your buck piston for a 390 build, but technically it’s a 360 piston and I think I lost a little compression going with it, but I wasn’t looking for massive horsepower.
Anyways, I wanted to share my thoughts on the JBA tri Y headers 6656s. When it comes to headers for the 390 with the 14 bolt head pattern really the only available are FPA which are the most commonly used, and then JBA makes the headers I went with. I found these headers on sale on amazon for about $700, but commonly they are found for $850-$900 which are slightly less than the FPA headers. I also bought the JBA powersteering drop down bracket as my cougar has power steering. My main reason for going with the JBA was the fact they are stainless steel and less expensive than the FPA headers. First impressions…
The JBA headers come not polished. They are very heavy duty and appear to be of very high quality. After three pulls on the dyno they did get a brownish and purple tint to them in areas. They are listed to fit 1969 390 mustangs, and are listed to fit power steering (with the drop down) and c6 automatics. I first tried to install these headers as one with the engine and transmission. Some people say installing them all as one unit can be done in 20 minutes… There are even pictures of the mustang guys doing so… Supposedly at least. I found this method to be impossible… There is just not enough room to get the headers to clearance past the shock towers and steering box. Also this method tends to beat up your engine compartment. I ended up laying the headers in place and dropping just the engine on top of them. This method worked but it literally took about 5 hours to get all the bolts in as the headers are practically right up against the shock towers. You literally have about 1/4" space between the headers and the shock tower reinforcement plate. I used a 2x4 to rock the engine back and forwarth to make space for the wrench to get in there. I then jacked the c6 up from under the car and it BARELY makes it past the headers… You have to go at and angle and then jockey it around back into place.
Overall these headers DO fit… But I would not go through what I went through again if given the choice. They fit extremely tight and it took 3 days of agonizing trial and error to figure out how to get them to fit. Also the gaskets that came with the headers needed to be modified in order to fit. These headers are stainless, and are supposed to be heavy duty 409 stainless. I found these headers were magnetic which is sightly concerning. I will be posting pictures shortly of the headers and how tight they fit in the car. Hopefully this information helps as I found there to be little information on these headers when I began researching headers for the 14 bolt head. Feel free to comment, thanks.
Is that Single plane mani, or the dual plane. I have the dual, very streetable.
Thank you for posting your results. In the next few months I will be wrestling a similar combo into my '67. I have seen a vid of Mustang guys dropping in the whole set too, but they were the Hooker headers, which is what I was looking towards.
Same set-up, C6 and PS with the drop bracket, and I am looking at the Hooker 6114C Long tube, as I have the Performer heads with the 16 bolt pattern. I hope it goes better than that, sorry your’s were such a PITA.
Shortly after writing my review I got the car to the shop to get a 2.5" exhaust fabbed up with magnaflow mufflers along with a 3.5 rear gear and a Detroit truetrac rear end. Long story short on the way back from the shop the engine failed (two spun rod bearings) It was awful to have to pull everything back out but the engine builder stood behind his work considering the engine only had about 4-5 street miles on it after the dyno. Upon tear down it was discovered the top end overoiled due to using the incorrect style pushrods (oil through) based on the cam manufacturers recommendation which ultimately caused lack of lubrication on the bottom end.
My builder is great and took care of it. He decided to do more port work to the heads while he had the engine specifically on the exhaust ports. This time around on the dyno with all the same parts the only difference being the additional port work it made 380hp! Nearly 60+hp over the original dyno. Now just gotta get that beast back into the car!
Sorry for the bad news about your engine, but good news on the re-build/re-tune! So you are running non-oil through pushrods now? What about the oiling for the rocker arms, is that an issue?
BTW, my Hooker long tube headers were a PITA as well.