smon

i swapped my 75 350 for a new year one 350 and it wont idle in drive very well but it does fine in neutral. I keep getting told that I need a new tq converter. I believe the stock converter has a stall speed of 1800? so I figured somewhere around 2400 would fit this engine better. I dontknow much about this so I figured I would get some advice that I know i can trust.

what are some good brands at a reasonable price?

sean

DC3

If you don't mind spending a little money to get this right, take your car over to Complete Auto at 37th & Slide and have them put it on their dyno. Ted can read the curves and tell you what size you need. He dyno tuned my '73 a couple of months ago and did a great job. He told me I could benefit from a different TC but I won't bother to change it as I plan to upgrade to an OD tranny and will address it then.

DC

smon

Hey DC3, I didnt know anyone from Lubbock was on here.

Whats your idea of "a little money"? Would it include tuning? I have to change the front seal on my tranny so i figured that I would swap TC since I didnt durng my swap. But my car could sure use some tuning.

Sean

at3erdbase

Cam and rear info are needed provided you are using the stock 400 trans

The cam tells the rpm range and you need to know what you have. cr, heads intake misc... mean nothing. . they may account for power, but do not change you power curve

Note however that a free flowing exhaust is going to give you a few hundred more rpm, but I would say they are mandatory if you are looking for power.

I would also add a shift kit to your setup and be sure to run trick shift fluid and a trans cooler

Your cam has a duration that tells your valve timing.

Say you have a cam with a 216 to 220* duration. You would use a converter of 2400.

hope this helps

smon

I figure this is the easiest way to tell you guys the info.

http://www.yearone.com/serverfiles/f...ain2.asp?cat=Q

I have H sidepipes with max flows. stock q-jet stock trans-i thought 350. and stock rearend. If you need any other info let me know

Sean

That link will only take you to the front page for some reason, its the pc1 crate(400hp 350).
but the cam duration is 218*/228*

DC3

Hey Sean,

I think Ted gets $150 per hour for dyno tuning. I had a whole bunch of little things wrong with my car so I ended up paying for a few hours of dyno time. I doubt it would have taken more than an hour if all he had to do was adjust the carb. So mine was an expensive tune but worth it to me.

You can minimize the cost by doing as much as possible yourself before hand and having him do as much as possible off the dyno. I forget his labor rate for non-dyno work but it was a lot less than $150 per hour. Assuming no tuning was needed, I don't know what he would charge to make a couple of dyno pulls to determine the TC size but it shouldn't be too much.

DC

smon

Im gonna go with about a 2800 stall speed but i would like to know what brand to go with. has anybody had any problems with B&M or hughes. Hughes has a 3,000 that is cheaper and what I am looking for, but i dont want a piece of junk. I'm looking through summit and jegs, what else is out there within a reasonable price range.

75 Red Vert

Sorry to jump in here with an off topic question, 75VetteHelp, but can I see a picture of your engine? I am seriously considering putting a Year One crate in my 75 in front of a 4 speed. Are you happy with the engine?

smon

75 red vert, the engine is great. Lots more power over that stock l-48 (just about anything is). I havent had any problems and the price is great compared to other engines with similiar power. Just know that your going to spend some money on a new hood because it wont fit under stock. It was a perfect fit except for the water pump hit a timing chain cover bolt. I used a grider on the water pump to get it to fit right. heres a pic

75 Red Vert

Thanks for the pic. Looks great in there. Think you can go with a thinner air cleaner or is the carb just too high.

70ZZ3 96LT4

The air cleaner clearance problem could be solved with a "drop down" type open element air cleaner. GM produced this type of air cleaner for Corvettes. My 68's original air cleaner came from the factory on a QJet carb. I installed a 6210 double pumper Holley spreadbore many years ago, 1974, and used the factory drop down air cleaner after a minor modification of relocating the fresh air supply outlet from the air cleaner base.
When I put my ZZ engine in my 70 I bought from GM a new drop down air cleaner to install on the Holley double pumper. My crate engine has a intake that mounts the carb higher than the original 350, the drop down air cleaner allowed clearance without changing the hood.

gingerbreadman1977

can you just raise your idle so it doesnt stall. i think around 700 in D would be about normal.

76 sting

I could be wrong but I do not believe that a stall converter has nothing to do with how a engine idles. However you will like the performance of a good stall converter, but I would also change your gears at the same time. What gears do you have in the car now?

I too had (1 year ago) the 350 Year One engine. Stock gears 3.08 stock converter etc. still kinda slow so I changed the gears to 3.50 and a TCI Break A Way and bingo instant tire shreader.

I then upgraded to their 383 much better combo...unfortunaltely i trashed that one too and now a hand built 383 is the ending result.

smon

Thanks for all the help guys. I do have stock gears 3.08, and I will change those out at some point, but not right now. Being a college student, I buy parts as the money comes in(which is slow).

As for the hood clearance, That is a drop down on my engine in that last pick. I had to run a spacer under the carb to get the bolt pattern to fit my q jet. If you changed carbs to avoid the spacer(square bore? I cant remember which fits), then you might get away with a drop down cleaner base. Here is a pic that shows the height of just the carb from the side and there would be no space for anything else.

70ZZ3 96LT4

My 70ZZ3 (typo error I made) is really a 70ZZ1 crate engine, this GM crate engines intake being of the early offering, bought in 1991, has an intake designed much like the original Corvette LT-1 engines intake, higher mounting flange than my stock original engine 350/300.
The ZZ1 intake is a square bore, not spread bore design. I had a Holley 6210 double pumper spreadbore on my original 350/300, bolted right on the QJet profile intake. Thought I would try and use the Holley 6210 spreadbore with a spacer on my new GM ZZ1 crate engine. Not enough hood clearance even with a new GM drop down air cleaner. So I bought a new Holley square bore double pumper and have no problems with the original hood clearance using the high rise intake on the the GM crate engine.

76 sting

College student....save your money and do not get the stall converter. In your case it will not be enough bang for the buck unless you do both gears and stall converter. Hold on to your money in these rough times.

PETE 79

The B&M converters are real junk and have no torque multiplication at all. They just slip to a certain rpm and thats all. I use Pro Torque converters and work great and the one I have in my 79 has a 3.0 STR and even with only a 2400 stall, it still launches the car very hard! Im going to send it out and have them loosen it about 200-300rpm and it should work perfect. They do this for free and I just pay shipping. I had a TCI which are better than B&M with the same stall speed and there was a very big diffrence when I swapped it out for a Pro Torque!

vetteguy75

I too have a 75 and just recently changed the stock 165hp to a 300hp GMPP Crate Engine. Same problems existed that you have (rough idle ind Drive and smooth idle in Park or Neutral) Tried everything in the book to get the engine to idle somewhat smoothly. FINALLY decided to raise the stall speed from the stock 1600 to 2300. WORKED PERFECTLY!!! Idle now is alot smoother in Drive, more pick up and faster response. Had it done professionally at the local speed shop with an excellent reputation. The owner explained to me that the stock converter was "matched" to the lower hp, lower torque engine of the 70's. And since I put a more powerful engine with more torque, the transmission was "fighting" the engine...that's why it idled rough in Drive and not in Park or Neutral. I am SOOOOOO glad I did the swap.

Good Luck!!