I installed a set of black Hooker 2224 Side headers on my 77 L48 4spd. and I ran into a few issues and I am looking for advice from others who have done this install. Its been at least 25 years since I installed a set of headers on a SBC.
One of the drivers side header tubes hits the rubber gasket under the body near the rocker panel molding. Do I just trim it away?
All of those tubes are extremely close to the underside of the car. I would have thought they would have had a little space between them and the underside of the car.
I had to remove the drivers side header and dent it (using a large socket and hammer) so that it would clear the steering box. It was directly where the Hooker emblem is riveted to the tube. Is this normal? It looks like I might need to dent it in a little more but my plan is to use a pry bar once everything is buttoned in and the side pipes are installed. Its about a 1/8" away now which might be a little too close.
Lastly... and most importantly...I snugged up the bolts and the top parts of both the passenger side and the drivers side header flanges don't look like they are snuggly against the engine block. It looks like there is a space when looking straight down from the top. I am thinking that possibly the headers are hitting the underside of the car on both sides and preventing the headers from tilting up anymore so that they will seat correctly with the engine. Would this have anything to do with having the car jacked up from the frame on both sides 18"? BTW... I didn't use the gaskets supplied from Hooker. I bought a set of the drop in Mr. Gasket gaskets.
The car looks great with the headers installed and they were super easy to put in but to my eyes... the headers don't look like they are seated correctly to the block. It could be correct but its been a while and it doesn't look correct to me.
One other thing... the Hooker Header instructions clearly state that I would need to remove the rocker moldings and do some trimming to get the headers to fit. Since I was test fitting them anyway... I didn't remove the moldings and they don't hit anywhere near where Hooker says I need to trim. The tubes are hitting the underside of the body inboard from the rocker molding or the channel where the rocker molding is located.

 

One more probably stupid question.... the Hooker Headers came with 12 bolts. 10 of them are 1/2" long. 2 are 3/4" long. I assume the 3/4" are for use if the alternator bracket needs to be used. I don't need it. By the looks of it, the short bolts fit but they don't seem to have much thread into the block so I went out and bought a set of Spectre 46723 header bolts which are allen head style. They are 7/8" long. Is this too long for my motor? I see that ARP makes them but the length is 3/4" and I have read that many people use 1".

 

make sure you have the correct motor mounts installed. I always used the allen head bolts with the dead aluminum gaskets. A little trimming here and there but no big deal.

 

The motor mounts are stock from 1977. The original motor has never been out of this car.

 

Check your door gap at the top and bottom. If it is spreading then you need to support the front of the frame near the engine. This will affect the fit of the headers in relation to the body.

 

Door gap didn't move. Front cross member is supported. It looks like I may need to trim the body per the hooker header instructions which isn't something I wanted to do

 

I did some looking around under the car and it certainly looks like I will need to trim the body exactly where the Hooker directions show its required. I loosened up the header on the drivers side and when I push it up from the collector it hits the fiberglass behind the rocker molding before it fully seats on the motor. Its VERY slight but it does hit. I really didn't want to cut the body but since its behind the molding it won't be seen anyway. I am going to do a search on this forum to see if anybody has had to cut the body before I actually do it. I would prefer NOT to cut the body.

 

I had to trim my '77 for the Hooker side pipe header to fit.











Trimmed to clear the top primary tube.



Both sides had to be trimmed.







For me, the end result was worth it.

 

I agree. Your car looks awesome.

 

I got the rocker moldings off and removed the headers. I need to trim the lower body a little bit. No big deal. Once I get these headers sorted out and fitted well enough I will remove them and paint them up with high temp paint. They are all scratched up from me installing and uninstalling them a few times already. I also had to dent up one of the driver side tubes because it was hitting the steering box. Again... it didn't have to put any major dents in it but it definitely hit. So far... so good...

 

I guess I was lucky because I did not have any clearance issues requiring dents in the tubes.
I also plan on removing mine and painting them with some high temp paint.
Did you do anything for heat shields?
I'm not running any right now.

 

I checked and my headers arent hitting either. If i push them up one of the tubes hits the bottom of the car but once they are tight they dont hit. I test fitted the side pipes and they line up with the holes in the frame perfectly.
What was throwing me off was how the header flanges look seated to the heads. They dont sit flush because of the raised welds in the header tubes. Obviously thats what the gaskets are for. Next step is to take them off and paint them with header paint and Por 15 the frame under the rocker panels.