Discussion Forum - Northstar Chevelle Club

jim larson · 2K+ Club

Value of 200R4 with multi fit as a core?

Lost in the 60s · President

The going rate for a core is $100. Unfortunately, the 200 has fallen out of favor with many for the 4l60 and 6l80 transmissions. Multi-fit does provide a larger field of sale, but I don't know how popular they are outside of the Chev community.

jim larson · 2K+ Club

Lost in the 60s wrote:
The going rate for a core is $100. Unfortunately, the 200 has fallen out of favor with many for the 4l60 and 6l80 transmissions. Multi-fit does provide a larger field of sale, but I don't know how popular they are outside of the Chev community.

I have been reading some articles, don’t know much. Seems it might be an easier swap to a 66 And give you an overdrive as compared to my current tH 350. I guess some are more valuable than others. Sounds as if it might be good for a lower HP & TQ car like a convertible with say under 400hp&tq.

Jon H · 1K+ Club

When I had the 200 put in my car in was guaranteed up to 600HP. I only have 450 which I probably use harder than I should some days and zero issues.

Lost in the 60s · President

It would be a great trans in your '66, Jim. Like Jon said, they can be built for a lot of hp. I think mine is built to around 500 and I have half that...

Chris R · 2K+ Club

They are quite popular with the Pontiac crowd too. Especially since the BOP bolt pattern style 200R4s account to the majority of cores you find now. At least that's what I have learned. Both patterns will bolt up fine none of the less.

jim larson · 2K+ Club

Lost in the 60s wrote:
It would be a great trans in your '66, Jim. Like Jon said, they can be built for a lot of hp. I think mine is built to around 500 and I have half that...

Thats kind of what I was thinking, auto is a lot easier to drive; but not as much fun, as the current th350 shifts around 3800. Rachael can even drive it. Out on country roads with no traffic because of the brake issue. With the engine 96% chance of coming out this winter, it only make sense to do a tranny swap at that time.

Lost in the 60s · President

jim larson wrote:
Lost in the 60s wrote:
It would be a great trans in your '66, Jim. Like Jon said, they can be built for a lot of hp. I think mine is built to around 500 and I have half that...
Thats kind of what I was thinking, auto is a lot easier to drive; but not as much fun, as the current th350 shifts around 3800. Rachael can even drive it. Out on country roads with no traffic because of the brake issue. With the engine 96% chance of coming out this winter, it only make sense to do a tranny swap at that time.

That is very high for a TH to be shifting under normal driving conditions. There is a vacuum modulator on that trans. Have you followed the vacuum line from intake to modulator, to make certain there is no leak ? If so, have you removed the hose from the mod and plugged it to see if the vacuum at idle changes ?

It could be the vacuum is too low to trigger a shift at lower speed and you could get an adjustable modulator to lower that shift point.

Larry Lucast has stated he is willing to sell his 200r4. If you are seriously considering this, I would be in touch with him.

jim larson · 2K+ Club

Lost in the 60s wrote:
jim larson wrote:
Lost in the 60s wrote:
It would be a great trans in your '66, Jim. Like Jon said, they can be built for a lot of hp. I think mine is built to around 500 and I have half that...
Thats kind of what I was thinking, auto is a lot easier to drive; but not as much fun, as the current th350 shifts around 3800. Rachael can even drive it. Out on country roads with no traffic because of the brake issue. With the engine 96% chance of coming out this winter, it only make sense to do a tranny swap at that time.
That is very high for a TH to be shifting under normal driving conditions. There is a vacuum modulator on that trans. Have you followed the vacuum line from intake to modulator, to make certain there is no leak ? If so, have you removed the hose from the mod and plugged it to see if the vacuum at idle changes ?
It could be the vacuum is too low to trigger a shift at lower speed and you could get an adjustable modulator to lower that shift point.
Larry Lucast has stated he is willing to sell his 200r4. If you are seriously considering this, I would be in touch with him.

Thats only on WOT. for Example when stepping down into passing gear at around 40 mph and then keeping it to the floor up to about 90 mph. Or stepping down at a rolling stop. Not sure just driving, think 1st to 2nd about 15-20 mph and 2nd to 3rd about 25 mph to 35 mps. I have check the modulator line for leaks. found none, but who knows if I did it right.

Lost in the 60s · President

OK, that's different. Sounds like the kick down cable needs to be adjusted to pull out further for a higher rpm shift at wot.
The modulator, itself, could be leaking vacuum. All you need to do with that to check it, is pull the hose off and plug it to listen for rpm change, or crawl out from under and check your vacuum gauge.

jim larson · 2K+ Club

Lost in the 60s wrote:
OK, that's different. Sounds like the kick down cable needs to be adjusted to pull out further for a higher rpm shift at wot.
The modulator, itself, could be leaking vacuum. All you need to do with that to check it, is pull the hose off and plug it to listen for rpm change, or crawl out from under and check your vacuum gauge.

I disconnect my vacuum gauge and hooked up the booster as normal; but will plug he hose to the modulator and see if I hear anything. I have heard that a bad check valve at the booster will let the booster lose vacuum and the brakes will kind of fade. I wonder if that could be the issue as the brakes feel good at first and then the last few mph or feet they seem like their gone?

Lost in the 60s · President

No, I have pulled your check valve twice now and there is good vacuum in the booster.
You can check that yourself, buy pulling it out after the car has been run and then sat for an hour.