'79 Federal Heat Exchangers

[patayres]

Hey guys. I've posted a similar topic at the other site but would like to to get the IAC Forum's take on the matter.

I was able to pick up the heater boxes & necessary tin/tubes/brackets from a '79 fed engine for cheap. I am looking to use this system when it becomes necessary to rebuild my current engine (consuming some oil now but compression is still pretty good - 120+ all around), which is a stock 1800 EFI. If all goes as planned, rebuild will be a Camper Special.

Other than the square/oval ports, how does the 72-74 & 79 heater boxes differ? Any opinions on these systems over the stock 75-78 boxes (breathability, heating, etc)?

Thanks!

[bretski]

Aside from the square/oval port issue that you're aware of, I think the main thing you'll run into down the road is the issue of 1-year only parts (read: scarcity).

[Amskeptic]

Other than the square/oval ports, how does the 72-74 & 79 heater boxes differ? Any opinions on these systems over the stock 75-78 boxes (breathability, heating, etc)?

The '72-'74 heat exchangers dump directly into the muffler, and are blessedly free of the later joints and nonsensical circuitous exhaust path and bending triangular flanges that just love to leak.
Colin

[patayres]

This is the '79 fed heater boxes I just got:


I thought the '79 boxes dump directly into the muffler as well... or at least can if the '79 exhaust is changed out for the 72-74 system (same trapezoid mounts). I'm not in an area of Oregon that requires smog testing and don't plan to use the '79 crossover & exhaust. Probably a Thunderbird system.

Are these '79 boxes the same internally as the 72-74? I vaguely remember reading somewhere that one type has more internal fins for heating...