[Transporter]

Ok, maybe a dumb question and I'm sure the most common response may be to just stick a 200r4 in it, but I wanted to ask.


Putting together a nice clean little 69FB coupe out of a bunch of parts I have laying around, 3.23 posi rear, a warmed over .030 350 Pontiac motor that is brand new except for dyno time, and a worn out Turbo 350 that needs rebuilding.

I have run a 400 with a tall gear (287) and tall tires with a turbo 400 and it did rather well esp. on the 75mph hwy's out here.

But I am a little concerned that the 350 won't have the torque, so my question is a built T350 tranny with a 2.75 1st gear set and the 3.23's would be a nice setup overall, but maybe a bit buzzy at hwy speeds.

So I was wondering about putting a lockup converter in it to lower the cruising rpm's 300 or so???

It all sounds good on paper, my question is does it equate to real world? I'm not really needing the 4th gear of the 200r4, and just thought this would be an acceptable solution?

Thoughts?????

[1968GTO421]

See this thread: http://forums.maxperformanceinc.com/...=802771&page=2

Post number 31 is by member 77TRASHCAN. He ran a lockup TH350 in his car and it ran great, he said. You might PM him for details.

[Squidward]

When I ran a 3.23 gear, My 350 did just fine. It may have a tiny bit less locomotive power at low rpm's than a 400, but it will do just fine for street cruising purposes. Without lockup, it will buzz around 3k on the highway. Personally, I think you'd be fine to go with a standard TH350 build, and save yourself the expense of deeper 1st gear and lockup converter. Now if you already had a lockup TH350 unit on hand, then it might be a different story.

What cam?

[Transporter]

Originally Posted by 1968GTO421

See this thread: http://forums.maxperformanceinc.com/...=802771&page=2

Post number 31 is by member 77TRASHCAN. He ran a lockup TH350 in his car and it ran great, he said. You might PM him for details.

Thank you!

[Transporter]

Originally Posted by Squidward

When I ran a 3.23 gear, My 350 did just fine. It may have a tiny bit less locomotive power at low rpm's than a 400, but it will do just fine for street cruising purposes. Without lockup, it will buzz around 3k on the highway. Personally, I think you'd be fine to go with a standard TH350 build, and save yourself the expense of deeper 1st gear and lockup converter. Now if you already had a lockup TH350 unit on hand, then it might be a different story.

What cam?

3000 would be way more than I want to run, my 400/400 combo only ran around 2200 with 29" tall tires, I really liked that, I could tolerate up to 2600 or so, that is why I wanted the lockup, that 3000 constant rpm around here would be a deal breaker.

To be honest I am not sure on the cam, I bought the motor many years ago from a member on here, I did have it dynoed, I cant find the spec sheet right now but I believe it was around 390hp/450tq

Motor was supposedly built by a guy out St Louis way that is a Pontiac 350 guru??? I guess he runs a class winning 350 stocker???

That is honestly all I know.

[ponyakr]

"...Motor was supposedly built by a guy out St Louis way that is a Pontiac 350 guru??? "



Byron McElfresh maybe ? He built a 350 for the Engine Masters Challenge a few years back. He started the Pontiac Drag Racers Facebook page.

http://www.jalopyjournal.com/forum/t...llenge.933686/

https://www.facebook.com/groups/pontiacdragracers/

Instead of spending all that cash on a low gear set & lock-up converter, you might consider a high dollar stall converter, which will flash higher, but slip less, like the Continental converters were said to do. Surely there is some other converter company out there who can build such a converter.

Cliff said he's using a different company now. Might check with him & see how those converters are performing.

[Transporter]

Originally Posted by ponyakr

"...Motor was supposedly built by a guy out St Louis way that is a Pontiac 350 guru??? "



Byron McElfresh maybe ? He built a 350 for the Engine Masters Challenge a few years back. He started the Pontiac Drag Racers Facebook page.

http://www.jalopyjournal.com/forum/t...llenge.933686/

https://www.facebook.com/groups/pontiacdragracers/

Instead of spending all that cash on a low gear set & lock-up converter, you might consider a high dollar stall converter, which will flash higher, but slip less, like the Continental converters were said to do. Surely there is some other converter company out there who can build such a converter.

Cliff said he's using a different company now. Might check with him & see how those converters are performing.

Hey big thx, I think that was his name and he is on my FB feed, Ill send him a message!

[Transporter]

Originally Posted by Transporter

Hey big thx, I think that was his name and he is on my FB feed, Ill send him a message!

Ok Byron is the guy that built the motor, he said he thinks it 0.30 trw flats with lightweight pins shotpeened rods and reworked #47 heads with a performer intake, said it should be about 9 to 1 and he thinks the cam is a Crower 255/262@.050

[ponyakr]

"...the cam is a Crower 255/262@.050..."


That's obviously way too much cam for a pump gas street 350. IMO

I've never even ran a cam that big in any of my low budget 455 footbraker bracket engines.

A 256/262 adv Voodoo would be a LOT better, for under 5000rpm use.

http://www.lunatipower.com/Product.aspx?id=1774

That Crower would be better from 5000-7000. It's a nasty solid cam for drag racing only. With a 350 Pontiac, you'd need a at least a 4500rpm converter, & probably 488-513 gears.

And that cam will have no vac or low end torque, and may not idle below 1500rpm. In short, don't even think about running that cam in a 350 street driver.

http://www.cnc-motorsports.com/crowe...-camshaft.html

[Transporter]

Originally Posted by ponyakr

"...the cam is a Crower 255/262@.050..."


That's obviously way too much cam for a pump gas street 350. IMO

I've never even ran a cam that big in any of my low budget 455 footbraker bracket engines.

That is what I thought also, he was fuzzy on remembering but Ill know more when I check it, I hope it's smaller than that, besides, I was hoping it was a Hyd. Im not going to hold him to remembering, he built it about 8 years ago!

[Squidward]

Originally Posted by Transporter

3000 would be way more than I want to run, my 400/400 combo only ran around 2200 with 29" tall tires, I really liked that, I could tolerate up to 2600 or so, that is why I wanted the lockup, that 3000 constant rpm around here would be a deal breaker.

To be honest I am not sure on the cam, I bought the motor many years ago from a member on here, I did have it dynoed, I cant find the spec sheet right now but I believe it was around 390hp/450tq

Motor was supposedly built by a guy out St Louis way that is a Pontiac 350 guru??? I guess he runs a class winning 350 stocker???

That is honestly all I know.

To qualify my statement, those rpm's are what I would see running a 235-60-15, which is a 26.3"(?) tire.

If you have a legit 390hp 350, I bow to you. Nicely done!

[Transporter]

Originally Posted by Squidward

To qualify my statement, those rpm's are what I would see running a 235-60-15, which is a 26.3"(?) tire.

If you have a legit 390hp 350, I bow to you. Nicely done!

Hey SW, I was running a 275/60/15 on 10" rim on my other 69 bird, it was 28.80 if I remember right.

I just used Wallaces calculators and came up with 2600 at 70 with a 3.21 gear, that is close enough for me, BUT, I think you need the lock up to achieve that as I sure that is figured with a std. trans?

I guess I figured 390hp 350 was good, but not out of this world, after all Tom's stroker 301 made 500hp, so that I would consider top of the heap? I didnt have it built, just bought it all together, still looking for that spec sheet.

[Squidward]

Originally Posted by Transporter

Hey SW, I was running a 275/60/15 on 10" rim on my other 69 bird, it was 28.80 if I remember right.

I just used Wallaces calculators and came up with 2600 at 70 with a 3.21 gear, that is close enough for me, BUT, I think you need the lock up to achieve that as I sure that is figured with a std. trans?

I guess I figured 390hp 350 was good, but not out of this world, after all Tom's stroker 301 made 500hp, so that I would consider top of the heap? I didnt have it built, just bought it all together, still looking for that spec sheet.

I am a fan of the 350's. I run a 350 in my 67 FB. I still have yet to prove how much you can squeeze out of them. Making a big cube motor go fast is easier.

[ponyakr]

I bought a car that had a 350HO engine in it, which made 434hp on the dyno. But it had too much compression for pump gas, and the cam was a little too nasty for street cruising.

It would take just the right combo of parts to build a pump gas friendly 350, with 400 hp.

I'd say the easiest way would be with alum heads & a HR cam. But that would not be a budget friendly build.

With unported iron heads, and a very streetable HFT cam, I'd say 350-375hp would be a decent 350. I dare say there are not many 375hp Pontiac 350 engines running the streets.

I remember reading a build of a 350HO to almost exact factory specs. On the dyno it made almost exactly what the original advertised hp rating was--325-330. And that was with the #48 heads. So, if you use heads which produce less compression, you'll have to choose the correct cam to make as much or more power than the 350HO.

Of course there are other things that can increase the power. The Pontiac guys who race the low compression 350 in Stock & SS competition are making big power with 'em. Bill Rink is one guy who has raced some high powered low compression 350's in his '74 GTO, in both Stock & SS. Mike Morgan also has a quick '77 SS Bird, with low comp 350 power.

I think most of these engines were built by Parsons & Myers. Don't think they'll give out any free info on what they do to get all that power out of a Pontiac 350.

[Cliff R]

There is really very little if any advantage of having a LU converter with a TH350 these days. Converter technology is really that good, and they are very well coupled at cruise, especially with taller gearing........FWIW......Cliff

[Skip Fix]

Chris at Continental built me a 13" TH350 lockup convertor for my 81 TA and the 400 -just never hooked up the lockup.

[Transporter]

Originally Posted by Cliff R

There is really very little if any advantage of having a LU converter with a TH350 these days. Converter technology is really that good, and they are very well coupled at cruise, especially with taller gearing........FWIW......Cliff

Thanks Cliff appreciate the input, guess my question is IF I was not to use a LU, and a really good converter, how much more rpm over a stick would I see in cruising situations, 100, 150? That I could live with, just REALLY trying to stay out of that 2750 and up range.

Also what would you aim at for stall speed, 3200?

[Transporter]

Originally Posted by Skip Fix

Chris at Continental built me a 13" TH350 lockup convertor for my 81 TA and the 400 -just never hooked up the lockup.

Like I said Skip, it may be best to just bite the bullet and have a 200r4 built, was just trying to get a nice compromise with what I had.

[Skip Fix]

One of my local tranny guys said the TH350C lock up should be as strong as a regular TH 350.

I've been running a TH350 in my 78 (non lock up) for a while running high 10s to low 11s. The 200R will need a lot of better hard parts if you have much TQ.