307 questions and options

[regulz]

hey everyone, im new here, and figured this is the best place to ask.

i have a regal with a 3.8 in it right now.

well i came across a regal with a 307 in it the guy said i could get everything for free off it and figured an 8 would be better anyday over the six. :?

i would just drop in a crate motor but i need to keep all my smog/emissions equipment.

now for the questions....

*307 questions
i got a 87 so i read up on the whole 5a heads and the diff intake thing and besides a cam what else could i do? is there a set of smog legal headers out? only reason i ask is because my manifolds have extra tubin on them and im unsure if they all had that or i was unlucky enuff to get a california smog car..keep in mind im gonna rebuild it if i go this route.

*307 to 350 questions...
ok here is where im very unclear with things..
i need to keep all my smog and electronics...
would all the 307 electrics/ecm and smog go onto a crate 350 block and work?
would a chevy or oldsmobile block make a difference being the intakes are wider?

if anyone can help i appreciate it, money and my time is tight, i rather have a 350 but if i have to go the 307 route to keep all the smog i guess i gotta do what i gotta do.

 

[joe_padavano]

hey everyone, im new here, and figured this is the best place to ask.

i have a regal with a 3.8 in it right now.

well i came across a regal with a 307 in it the guy said i could get everything for free off it and figured an 8 would be better anyday over the six. :?

i would just drop in a crate motor but i need to keep all my smog/emissions equipment.

now for the questions....

*307 questions
i got a 87 so i read up on the whole 5a heads and the diff intake thing and besides a cam what else could i do? is there a set of smog legal headers out? only reason i ask is because my manifolds have extra tubin on them and im unsure if they all had that or i was unlucky enuff to get a california smog car..keep in mind im gonna rebuild it if i go this route.

*307 to 350 questions...
ok here is where im very unclear with things..
i need to keep all my smog and electronics...
would all the 307 electrics/ecm and smog go onto a crate 350 block and work?
would a chevy or oldsmobile block make a difference being the intakes are wider?

if anyone can help i appreciate it, money and my time is tight, i rather have a 350 but if i have to go the 307 route to keep all the smog i guess i gotta do what i gotta do.

First, if money and time are tight, drop in the stock 307 along with all the emissions equipment and get it running. You can work on the swap later. You will need the computer and wire harness as well as all the under-hood emissions equipment. The 307 wiring has some key differences from the V6 wiring. Also, be aware that the 307 in that Regal is an Olds motor and has nothing in common with the 307 Chevy from the early 1970s.

Second, emissions requirements vary by location, so be sure you understand exactly what's needed. The general rule of thumb is that you can always swap a newer, cleaner engine but you can't swap an older one. The newer engine needs all the emissions equipment that it originally came with.

Third, as with the 307s noted above, there's a big difference between an Olds 350 and a Chevy 350. These are two completely different motors and there is ZERO parts interchange. Even the bellhousing bolt pattern and the motor and frame mounts are different, so you can't use anything from the 307 Regal on a small block Chevy. On the other hand, you can legally swap an LT1/LT4 motor into your G-body if you get all the mounts, accessory brackets, and emissions gear FOR THAT MOTOR.

Finally, having said all that, the 350 Olds is externally identical to the 307. Others have successfully swapped an Olds 350 (and even a 403) in place of a 307, installed all the emissions gear, and passed emissions. If you paint the Olds 350 or 403 to look like the 307 and use all the 307 emissions gear and accessory brackets, I doubt most emissions test technicians (or anyone else) could tell the difference. Again, technically this would not be legal, but the odds of being found out are very small. Makes a nice sleeper... :wink:

The electronic Qjet on the 307 only uses the computer to control mixture on the primary barrels. The secondaries are fully mechanical just like any other Qjet. You can swap secondary metering rods to your heart's content to feed the larger motor.

 

[85t5mcss]

Other than no parts interchange, I agree with everything joe said. The Thermostats will interchange.

But, I would start with the entire engine/trans swap and get it running. Then start on your mods.

I am unaware of Emission headers for the Olds engines.

 

[joe_padavano]

Other than no parts interchange, I agree with everything joe said. The Thermostats will interchange.

Well, OK, cap and rotor also... and the carb base gasket. :lol:

But, I would start with the entire engine/trans swap and get it running. Then start on your mods.

I am unaware of Emission headers for the Olds engines.

Are you looking for C.A.R.B. exempt headers? I'm not sure this is a real problem since the A.I.R. tubes go into the heads, not the manifolds.

 

[85t5mcss]

OK, I forgot the cap, rotor, carb gasket and dist gasket. I was unaware of the smog tubes going to the heads. I haven't dealt with an emissions Olds for a while, possibly never. Mainly work with Chevy. Thanks for clearing that up.

 

[85 Cutlass Brougham]

The biggest question with emissions would be where you live. If you live in California or Colorado, or anywhere else that goes by CA standards it will be difficult without an amazing amount of work and research. However, it can be done and no doubt has been done. If you live somewhere without a hard core visual inspection your job is much easier. A friend of mine in rural New York says all they check there is for the presence of a catalytic converter and they never pop the hood. So, long as you have a cat and pass the sniffer, you're golden if you live there. If you live in Florida ( And we don't get smog tests re implimented) like me, you have no vehicle inspections of any kind. In that case, anything goes unless a cop pulls you over and wants to screw with you ( rare, but it happens as I have heard of one or two incidents). If you live in a state like that, don't piss off the cops or street race and you will be fine.

 

[Vern]

Joe has the plan. You can acquire an Olds 350/403 even with moderate performance mods use all the emitions brackets etc from the 307 and have you a nice legal looking smog passing car. You can yank the 307 & all emitions etc put it on the garage floor until you have a 350/403 acquired and ready. In the mean time drive the ole 3.8. If you swap the 3.8 for the 307 you will gain a little power and a better sound but will be disapointed with the lack of performance regardless of cam & headers.