Header Hell!

[unclewill]

Swapping my new 482 into the '69 Torino Cobra - the iron (6090d) headed 427 came out just fine, everything was going great, now I'm battling the headers!  They weren't that bad coming out, or going in when I installed the 427 last year, but now they are waaayyy tighter.  Do the BBM heads differ from OEM iron in the exterior dimensions?  Any tips on getting the bolts in without stripping?  I'm thinking I may grind the tips to a dull point to help get them started.  Has anyone else experienced a problem like this?  The gasket, header hole and head holes line up very close, and I have 5 in already, but the last few are having trouble starting cleanly...

[Drew Pojedinec]

Did you use the same exact motor mounts?
Is the engine siting straight and not tilted?
With less weight due to aluminum heads (and possibly the hood not on yet) is front of the car higher in the air creating a space issue?

[fastback 427]

I leave the motor mounts loose until headers are on, you can usually get half inch movement either way.

[unclewill]

Everything is the same, I'm only swapping the long block.  All the mounts are loose, too, the engine shifts around easily with the hoist.  Today I'm going to try taking out the motor mounts (again!) to get even more movement.  Thanks for the suggestions, guys!  If I ever say something like "I'll just swap in an all aluminum 511" stroker no problem!" please feel free to slap me in the back of the neck!

[thatdarncat]

I don't have any experience with BBM's so I don't know for sure, it's possible they are thicker in the exhaust flange, or across the whole head, you should be able to measure. It's also possible your 427 heads have been surfaced on the exhaust side enough over the years that they are thinner than original. One other thought I don't know the answer to - are the exhaust ports raised on the BBM's? That will make it harder on a shock tower car.

[cammerfe]

Years ago, when I put a 427 in my almost new '67 Cougar XR7GT, I used headers on which the flanges had been cut off and swapped to an 8-bolt all-up-'n'-down pattern. I'd suppose the job wasn't done in a jig and, I, too, had a degree of trouble getting the bolts started.

Ultimately, I bolted-up the passenger side, tight, with the engine swinging from the cherry-picker, put the driver's side header in the engine compartment loose, and then lowered the engine almost into place. With that degree of looseness, it was possible to get everything started and then tightened. Make use of the slotted, notched-out lower middle locations and get those bolts well started before you hang the header on them. This helps to get the header in the right position to assist in getting the rest of the bolts in without interference.

KS

[Joe-JDC]

Block not decked, heads not milled, might make them higher up in compartment than the old parts.  Most iron heads have been milled over the years making them shorter and easier to install headers.  Might want to reposition the jack stands so that the shock towers aren't being forced inward with the engine out.  I have had engine compartments close up just enough to create the problem you describe.  Joe-JDC

[fekbmax]

All aluminum 511" ..  sweet.. all the headache will be worth it..

[unclewill]

12 hours of pain and agony and the headers are in.  Had to beat them (ahem, modify) into shape to fit around some parts of the shock towers.  Toughest problem I've had with any repair I've done in 35 years - and I had a diesel powered boat!
@thatdarncat - I think you are right, these heads definitely have more meat on them.
@cammerfe - I used the exact same method as you describe and it worked.
@Joe-JDC - I think you are right too - the iron heads were likely milled.  They cc'd at 61.5, factory was around 64cc.
@fekbmax - Stop it!

[bn69stang]

As far as the BBM s go , i was able to put my 28 in with both headers on and water pump to scatter shield with the use a of an engine leveler , front of car on the ground and back axle on jack stands .. Just the same as when i had the edelbrock heads on the motor .. Bud

[westcoastgalaxie]

If memeory serves me correctly bbms do have raised ports. I think header port wise the normal headers will bolt up they are just higher on the head. This does make for a wider motor package.

[unclewill]

I guess this serves as a reminder that FEs can be a tight squeeze even in cars originally equipped with them.  Thanks for all the great tips!