1968 emssions assembly/parts

[hurlbird]

I'm beginning the journey of gathering the smog parts I need for my 350 4 speed. I haven't found a definitive list nor a real assembly manual picture that I can use to assist me in getting all the parts I need despite having checked the typical sites. I would appreciate a list, link or assembly manual reference that would help me. My car still has the pump bracket and pulleys... I think that is it. Thanks all as usual!

[J_Speegle]

This is where lists like you request originate. Owner or builder has a need, does the heavy lifting and then shares with the masses   Maybe you'll get lucky and someone may have already done this.

To start you out

- Pump with plastic "filter"
- Pump pulley
- Exhaust Manifolds
- Thermactor (Check valves to head connection) system manifolds x2.
- Thermactor style cylinder head x2
- Check valves x2
- Bypass valve
- Bypass valve mounting bracket
- Hoses - 3. One for each side manifold to bypass valve and one form bypass to pump connection. All preformed
- Hose clamps Think there are 6 total but two different styles used
- Belt - will differ depending on your cars options
- Pump mount
- Pump adjustment arm and bolts. Top one has a large integrated washer
- Pump mounting bracket to head may have a round steel spacer. Doing all of this from memory at the moment.

Surely I missed something and did leave out hardware such as mounting bolts, exhaust manifold tubing details and such for you to determine  

MPC for 68 and later will have some general pictures of the assembly and parts. Will not always be exactly as production line but a reference

[hurlbird]

you are awesome and thank you very much!

[hurlbird]

I have never seen a smog exhaust manifold. Are they so unique that a non smog couldn't be machined to work properly?

[Coralsnake]

They are not significantly diffrrent, nothing ten minutes with a drum grinder couldn't do.

[hurlbird]

great that's what I hoped for... thanks

[Bob Gaines]

This is where lists like you request originate. Owner or builder has a need, does the heavy lifting and then shares with the masses   Maybe you'll get lucky and someone may have already done this.

To start you out

- Pump with plastic "filter"
- Pump pulley
- Manifolds x2
- Check valves x2
- Bypass valve
- Bypass valve mounting bracket
- Hoses - 3. One for each side manifold to bypass valve and one form bypass to pump connection. All preformed
- Hose clamps Think there are 6 total but two different styles used
- Belt - will differ depending on your cars options
- Pump mount
- Pump adjustment arm and bolts. Top one has a large integrated washer
- Pump mounting bracket to head may have a round steel spacer. Doing all of this from memory at the moment.

Surely I missed something and did leave out hardware such as mounting bolts, exhaust manifold tubing details and such for you to determine  

MPC for 68 and later will have some general pictures of the assembly and parts. Will not always be exactly as production line but a reference

I think it is a good idea to clarify that the "Manifolds x2" in Jeff's list are referring to the steel tube smog manifolds. These are visually and functionally different then the exhaust manifolds. Given the check valves attach to the manifolds on the list I have a high confidence level those are what he is referring to. I didn't want confusion .I also would like to add the special smog related alternator adjusting bracket to the list .

[TLea]

Depending on car build there are 2 styles of smog tubes. Also is it AC car? They have some smog differences as well

[J_Speegle]

I think it is a good idea to clarify that the "Manifolds x2" in Jeff's list are referring to the steel tube smog manifolds. These are visually and functionally different then the exhaust manifolds. Given the check valves attach to the manifolds on the list I have a high confidence level those are what he is referring to. I didn't want confusion. I also would like to add the special smog related alternator adjusting bracket to the list .

Adjusted and added a little to the list above, should have the first time, to list out the heads, exhaust manifolds and the Thermactor manifolds separately and in a better way. The only systems I've found and have pictures of for the application focused on here ( J code 68 engines) have the external Thermactor systems. Two systems were used that year for small blocks - external and internal so parts differ a bit. See the internals originally on C codes that year. But that's my findings at this point

Don't recall and haven't checked to see if there is a different dist, timing sticker or carb for the difference either like other years.

[hurlbird]

Car is NOT AC.

[TLea]

Distributor was different in the sense that all four-speed cars had a unique distributor and all four-speed cars has thermactor

[cascade-classics]

I have a main bracket available if you still need one.  PM me for details.

[hurlbird]

thanks Cascade that is one of the few parts I have. TLea what are the differences in the two tube types you reference? Thanks all...

[KR500]

thanks Cascade that is one of the few parts I have. TLea what are the differences in the two tube types you reference? Thanks all...

From My observations the earlier in the model year tubes have the ends crimped ( flattened ) closed and later tubes have a cap attached closing off the end of the tube. I have seen at least one engine that had one of each style tube.

[TLea]

thanks Cascade that is one of the few parts I have. TLea what are the differences in the two tube types you reference? Thanks all...

From My observations the earlier in the model year tubes have the ends crimped ( flattened ) closed and later tubes have a cap attached closing off the end of the tube. I have seen at least one engine that had one of each style tube.

Exactly. I would put changeover early-mid January