77 FJ40 Emissions Questions

[chitown40]

Hi all --

I have a beautiful mustard '77 FJ40 located in Chicago, IL. I recently purchased her from an truck-illiterate woman who only knew that it had a V-8 under the hood. After I brought her home I checked out the details of the conversion and noticed that the original owner many years ago swapped in a small block 400 and welded air tubes to custom headers (non-block huggers) which are connected to the stock air pump which was put on the small block motor. I recently passed Illinois emissions with no problem, but the passenger side header gasket in blown and I have a bad exhaust leak. The headers are pretty rusty and are on their last legs. The driver side exhaust also has a small leak in the pipe just in front of the muffler. The motor runs all right, but I am getting a lot of exhaust smell in the cab and some backfiring on acceleration. I will be adjusting the valves soon (as I have some loud clicking on the passenger side), but I'm pretty sure the exhaust leaks are causing the backfiring. My question is, if I remove the header and put on a completely new exhaust can I forgoe welding on new air tubes and reconnecting the airpump AND still pass emissions? I'd like to for simplicity and cost's sake, as well as use the air pump bracket for a future p/s conversion. The only thing is I need it to pass emissions because I will be using it as a daily driver (mostly on-road).

Thanks,

Rob

 

[Rice]

Rob ...
If you check out places such as summitracing.com you'll find there are several choices of headers that have air nozzles already welded in place and might be easily adapted to your engine. Be careful of the header leak you mention ... between it and the backfire and the clicking it could be telling you it's too late and you've burned a valve and if not continued driving will eventually make it happen.

 

[chitown40]

Rice,

Thank you for the info. I will go there and check out what they have. As the rocker arms clicking, it's not too bad and I already adjusted the rocker arms once...one or two were real loose before I did them. I may be hearing just exhaust noise now because of the leak...so we will see where I get the header replaced, or just the gasket if I can get the old headers off. A guy at a shop said he wouldn't touch it because the headers tend to warp as they get older and I may not be able to get the old one back on w/ a new gasket if it is in fact warped too much.

Rob

 

[Rice]

Something to help with the sealing and warping issue is to pick up some header studs. They have a higher clamping force than bolts and make getting the gasket and header lining up much easier. Summit will have them too.

 

[chitown40]

I'll check into that as well. I looked on Summit and only found Edelbrock's with air tubes, but I suppose it's a start. I think I'll start witht the gasket and go from there. Thanks again, Rice.

Rob