1G Tranny upgrade or synchromesh fix + clutch kit?

[kmandymac]

Hi guys!
So I have this n/a 6-bolt 1991 Plymouth Laser with a dead 6 bolt engine. I'm turbocharging it and building it to 500 whp.
My current engine is dead, so I'm replacing it with a 7-bolt swap that I bought in great condition. Now I have 2 problems:
1. My original clutch is 6-bolt so the new engine won't fit bolt-on. I need a new clutch kit, I guess.
2. My tranny makes a "grrrrrr" sound when shifting into 2nd and 3rd, I guess synchromesh is gone bad.

Considering the above, maybe it's better to replace the entire tranny? Are there any decent options for a 500hp build within the ~$2000 range that are still available in 2021?
Or will I be just fine if I repair the synchro and install a new clutch kit? If that's the best option, what would be a decent choice in the $500 for the kit range?

 

[pauleyman]

Hi guys!
So I have this n/a 6-bolt 1991 Plymouth Laser with a dead 6 bolt engine. I'm turbocharging it and building it to 500 whp.
My current engine is dead, so I'm replacing it with a 7-bolt swap that I bought in great condition. Now I have 2 problems:
1. My original clutch is 6-bolt so the new engine won't fit bolt-on. I need a new clutch kit, I guess.
2. My tranny makes a "grrrrrr" sound when shifting into 2nd and 3rd, I guess synchromesh is gone bad.

Considering the above, maybe it's better to replace the entire tranny? Are there any decent options for a 500hp build within the ~$2000 range that are still available in 2021?
Or will I be just fine if I repair the synchro and install a new clutch kit? If that's the best option, what would be a decent choice in the $500 for the kit range?

You don't need a new clutch. You need a new flywheel. If you're keeping the nt trans all else can stay the same. I hope you bought a 1g 7bolt. 2g 7bolt does not have any provision for motor mounts as they are on the trans front and rear on a 2g. If you swap to a turbo trans you need a new clutch also among other things. There are also axle differences etc. If you start swapping don't go in blind. Lots of info on this site. I would recommend heavy research first.

 

[kmandymac]

You don't need a new clutch. You need a new flywheel. If you're keeping the nt trans all else can stay the same. I hope you bought a 1g 7bolt. 2g 7bolt does not have any provision for motor mounts as they are on the trans front and rear on a 2g. If you swap to a turbo trans you need a new clutch also among other things. There are also axle differences etc. If you start swapping don't go in blind. Lots of info on this site. I would recommend heavy research first.

Yup, thank you. I know I need a new flywheel because that's what I got 6-bolt and need 7-bolt. So you're telling me the tranny from a naturally aspirated 1g DSM can withstand 500 whp? If so, that's great news.
I wanted to also upgrade the clutch kit for the durability purpose, like I'm not exactly sure the original clutch will withstand 500whp. Besides, the original flywheel is heavy with excessive metal, Ithought I'd maybe find something lighter and more durable...
Speaking of tranny, I thought maybe there are 3rd party swap options that are guaranteed to not be worn out. All I could find were track racing trannies for like $9000 and that's an overkill.

I did some research, problem is, most suggestions are from like 15 years ago. So I was hoping to have something suggested to me in this thread that is still available in 2021.

P.S.: Yes, it's a 1G engine. Matter of fact, it's a 6-bolt engine with a 7-bolt stroker crank, carved from stainless steel as a special order. It's one of a kind, it has the working parts of a 6-bolt but a 7-bolt junction, and it's also lighter than the original crank. Why on Earth would the engine's previous owner do it? I honestly have no idea, but the crank's condition is great, and the engine displacement is 2.4l now so I'm happy with it.
So, I can actually just keep my old 6-bolt crank while swapping motors, that's the easy and costless solution. But then again, if I do so, I'm keeping the old clutch and tranny, which were designed for a 145 hp car. Won't they fall apart when I put 600 bhp / 500 whp to them? I'm very scared they will. Also, I'll have to fix the synchromesh, which most likely means custom manufacturing a new one.

 

[pauleyman]

Yup, thank you. I know I need a new flywheel because that's what I got 6-bolt and need 7-bolt. So you're telling me the tranny from a naturally aspirated 1g DSM can withstand 500 whp? If so, that's great news.
I wanted to also upgrade the clutch kit for the durability purpose, like I'm not exactly sure the original clutch will withstand 500whp. Besides, the original flywheel is heavy with excessive metal, Ithought I'd maybe find something lighter and more durable...
Speaking of tranny, I thought maybe there are 3rd party swap options that are guaranteed to not be worn out. All I could find were track racing trannies for like $9000 and that's an overkill.

I did some research, problem is, most suggestions are from like 15 years ago. So I was hoping to have something suggested to me in this thread that is still available in 2021.

P.S.: Yes, it's a 1G engine. Matter of fact, it's a 6-bolt engine with a 7-bolt stroker crank, carved from stainless steel as a special order. It's one of a kind, it has the working parts of a 6-bolt but a 7-bolt junction, and it's also lighter than the original crank. Why on Earth would the engine's previous owner do it? I honestly have no idea, but the crank's condition is great, and the engine displacement is 2.4l now so I'm happy with it.
So, I can actually just keep my old 6-bolt crank while swapping motors, that's the easy and costless solution. But then again, if I do so, I'm keeping the old clutch and tranny, which were designed for a 145 hp car. Won't they fall apart when I put 600 bhp / 500 whp to them? I'm very scared they will. Also, I'll have to fix the synchromesh, which most likely means custom manufacturing a new one.

No. I am not saying you can keep that trans. I'm saying to even be able to drive the car changes have to be made.