I need a new engine in my 84 MCSS and have decided on a 350, since most of the things I have purchased so far will also fit a 350. My question is, if I get this engine : http://www.ebay.com/itm/1980-chevy-350- ... 500wt_1254 what other parts will I need (ie what can't I reuse from my stock set up?). I have heard a new flywheel but what about headers, torque convertor, wiring etc? My wiring harness is actually pretty much shot anyways, everything is a complete mess and melted. Where can I get a harness, or should it be supplied with the engine? Thanks for the help guys!
305 to 350 help
- Thread starter SLIM
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The Theory goes like this..
1) You can switch a 350 in for a 305 as long as you retain the "long block" as a whole and transfer the intake manifold and up, torque converter and back, and all the bolt on things like exhaust manifold and the pulleys and belts and things. This is because externally they are pretty much identical. The flywheel should carry over as well if the engine you are putting in is a 350 of the pre 1987 type.
2) things you DONT want to carry over are things like the Heads, cam and anything that is considered part of the long/short block.
3) Your 305 wiring harness is perfect for the switch. It is far easier to change from a SBC to SBC than a SBB SBO to a SBC. You won't need to snip wires and make new ones. If yours is burned up you should find a junk G Body car and get the wire harness out of that, just make sure its a SBC. OR you can just make you own out of your existing one. Just lay it all out on the garage floor and buy spools of matching colors and recreate your old one.
Exceptions to the Theory...
1) The engine you are putting in is way more powerful than the one you are removing. Questions you might ask, is my transmission/torque converter able to handle it?
Is your old Torque converter the same one that might be used on a 305? Usually SBC parts are listed as "sbc 305-400 pre-1987" meaning they fit and work well with anything in that range. In the case of a MC G body, in places like CA, in order to skirt the smog laws, guys switch in 350s for 305s all the time without any problems.
1) You can switch a 350 in for a 305 as long as you retain the "long block" as a whole and transfer the intake manifold and up, torque converter and back, and all the bolt on things like exhaust manifold and the pulleys and belts and things. This is because externally they are pretty much identical. The flywheel should carry over as well if the engine you are putting in is a 350 of the pre 1987 type.
2) things you DONT want to carry over are things like the Heads, cam and anything that is considered part of the long/short block.
3) Your 305 wiring harness is perfect for the switch. It is far easier to change from a SBC to SBC than a SBB SBO to a SBC. You won't need to snip wires and make new ones. If yours is burned up you should find a junk G Body car and get the wire harness out of that, just make sure its a SBC. OR you can just make you own out of your existing one. Just lay it all out on the garage floor and buy spools of matching colors and recreate your old one.
Exceptions to the Theory...
1) The engine you are putting in is way more powerful than the one you are removing. Questions you might ask, is my transmission/torque converter able to handle it?
Is your old Torque converter the same one that might be used on a 305? Usually SBC parts are listed as "sbc 305-400 pre-1987" meaning they fit and work well with anything in that range. In the case of a MC G body, in places like CA, in order to skirt the smog laws, guys switch in 350s for 305s all the time without any problems.
With the tall valve covers, it looks like a racing motor, not a street one. The dis is a vacuum advance one and is illegal for your car. Lack of specs listed on that page is not a good sign. You need to know the complete specs of that motor so you can set stuff up right such as the carburetor.
Flywheel, exhaust, and torque converter will all bolt up. But that engine will probably need a good 2 1/2" dual exhaust. And even though that engine will bolt to your stock converter and transmission, they most likely won't be able to handle the power of that engine for long.
I'm pretty sure you won't be able to use the stock computer with the new engine either, so you will need a non CC carb. New throttle cable and kickdown brackets may be needed too.
I don't know your budget or goals with the car. Also what's your current set up?
I'm pretty sure you won't be able to use the stock computer with the new engine either, so you will need a non CC carb. New throttle cable and kickdown brackets may be needed too.
I don't know your budget or goals with the car. Also what's your current set up?
Actually I already have a 2 1/2" dual exhaust, non computerized carb and distributor so I guess I'm 1/2 way there. My goal for this car is to have something I can drive daily but also still have enough power to take it to the track and smoke my buddies on the weekends 🙂
What are you running for transmission and rear, and what gears? And does your current exhaust have headers? What are you running for a carb, if it's a Quadrajet, what engine is if from? And what size tire do you have?
Not really sure what transmission/rear I have, I'm pretty new to this. I kind of think the transmission is a th350 but I'm not sure. It's an almost stock 84 MCSS if that helps. My exhaust does have headers, and the carb is an Edelbrock 650cfm
i think all gbodys came with a 350 transmission except the ones with a v6 they came with a 200r4. the 350 stock can handle more power than a 200r4 with out modification. you should be fine on that end unless you plan on having anything crazy
All gbodys did not come with a th350 or 2004r. Some, mostly the earlier ones also came with sad THM200s which is a 3-speed metric trans. Some other ones, also sadly, came with 3-speed TH250s which are similar to TH350s but even weaker. The THM200 and TH2004R can be identified by their pans. TH350s and TH250s share the same pan but TH250s can be identified by a band adjustment lug on the passenger side of the transmission that looks like about a 1-2 inch stud sticking out of the side of the case with a nut at the base.
All of these transmissions will not hold up to too much abuse especially with high miles and an engine that makes north of 300-350 lbs*ft of torque although the TH350 is generally believed to hold up the best in stock form of the above list.
All of these transmissions will not hold up to too much abuse especially with high miles and an engine that makes north of 300-350 lbs*ft of torque although the TH350 is generally believed to hold up the best in stock form of the above list.
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