question about catalytic converters

ok so the original 72 engine i had in my truck had a cracked block and basically everything is broken now. but my question is, do i need a catalytic converter for a newer engine on a 1972 and below car? i never knew if it pertained to the car or just the engine. thanks in advance

No converter needed on a vehicle that old.

No converter needed on a vehicle that old.


even if say the engine was idk a 1998 350?

Ouch! Maybe you should have said that earlier :)

I was considering the requirements for a cat regarding state emissions laws, which would mean 'no cat required'.

But any engine made in 1995 or later is OBD II. These engine control systems require a cat for proper functioning because they have 2 oxygen sensors, one upstream of the converter and one downstream. This means that converter function is integral with the ECM function. No cat means a 'check engine' light on all the time as well as stored codes.

The engine is also designed to use the ECM-controlled fuel and ignition systems, so you would need to retain the ECM, all sensors and the wiring harness.

You might be able to find a kit, intended for installing such modern engines in vintage hot rods that would make the swap easier, but you are still looking at lots of work to get this engine to work in your '72.

Unless you specifically want a OBD II engine in your truck, you are much better off to get a non-electronically-controlled carbureted 350.

Ouch! Maybe you should have said that earlier :)

I was considering the requirements for a cat regarding state emissions laws, which would mean 'no cat required'.

But any engine made in 1995 or later is OBD II. These engine control systems require a cat for proper functioning because they have 2 oxygen sensors, one upstream of the converter and one downstream. This means that converter function is integral with the ECM function. No cat means a 'check engine' light on all the time as well as stored codes.

The engine is also designed to use the ECM-controlled fuel and ignition systems, so you would need to retain the ECM, all sensors and the wiring harness.

You might be able to find a kit, intended for installing such modern engines in vintage hot rods that would make the swap easier, but you are still looking at lots of work to get this engine to work in your '72.

Unless you specifically want a OBD II engine in your truck, you are much better off to get a non-electronically-controlled carbureted 350.

ok man thanks