Would i benefit from a gear swap?

Hi, i was wondering if i would benefit from going to a 3.55 from a 4.10. Here's the specs of the combo.
350 Buick, Twin TBI Setup(In the making), TA intake, Pretty much stock heads, TA 310 Cam adv 3 degrees, 10:1 pistons, Rebuilt bottom end, 10" 3000 stall conv(footbraked to around 2800 and flashed to around 3700), Rebuilt TH-350 with transgo shift kit, 4.10 gear, and a 27" tire(295/50/15).
This would be coming out of a 4500 pound 90 lincoln towncar and going into a 2500 pound 88 mazda b2200. I do plan on going to the strip with this vehicle but it is also a daily driver in the summer.

In the lincoln, my best 1/4 was a 16.06@87.09 with a 60 of 2.569(best was a 2.350) and my best 1/8 was a 10.326@71.23 with a 60 of 2.350. I was going through the traps at around 4700 and shifting at 5200 with a redline of 5500.I was hoping for somthing in the 14's but o No:. The goal now is for 12's with some slicks.
Any advice?

Thanks,
Jeramie

 

you won't need anywhere near as much gear with the lighter car that you did with the lincon... that mazda should scoot with the 3.55 gears and get decent milage as well as keep the wear and tear down on the engine from high rpm's daily driving...

with that converter and a 2200 lb car, there's no need for 4.10's in my opinion

you could even throw in a 200R4 with a BOP bolt pattern and get low to mid 20's mpg :Brow:

 

I agree that the 3.55 gears would be plenty for a light vehicle but make sure you use a street freindly locker. Since your th350 is already done up I'd stick with that untill it breaks down and then go overdrive.

If I can get 20 mpg hwy with my 4000 pound car then I'm sure you could get 25 mpg with that light truck! or 10 mpg having an absolute BLAST!!!

 

You are going to lose a ton of stall by lightening weight of car keep this in mind.

Rod

 

Can't get any worse than the 8 mpg while babying it now. The motor really uses the gas when your on it. Last time at the track with E85 i started with a full tank of gas in the fuel cell and ended up with a little less than half after 12 runs. :TU: Doing my dual tbi i think i'll acomplish 2 things at once, gain istant control over the fuel and timing making it a little easier to tune, and make a EFI setup that no one has ever seen before except in their dreams. :laugh:

keep on keepin on,
Jeramie

 

you would benefit if you plan to do any highway duty and keep the TH350. IMHO, 2004r OD trans would be a better way to spend money than on the gear change.

If you want real power from that SBB you MUST get your hands on some ported heads. Short of nitrous i think thats the most power you'll get for the money. I keep saying this because it's the biggest regret I had with my 350. I'd NEVER do another one without well ported heads.

 

What TBIs are you using again?

 

I've got 2 TBI's from an 89 350 chevy truck and a 90 350 chevy truck. My plan is to make a sheet metal adapter and have them mount on like a 45 degree angle front to back. Then for an air cleaner i was looking at some oval ones and i found one that is like 17"x8" which would be an aditional 1.5" per side which, if i space the TBI's up far enough, should clear the intake. For the thorottle linkage, i'm probably going to fab some up thing like a dual quad linkage. To run them i'll be using a Megasquirt controller modified for spark and use a HEI with swaped internals from a chevy 7 pin dist. I believe the TBI's have 65pph injectors which would equate to having 8 32.5 pph injectors which should be enough to fed the engine. The only thing i'm undecided on is the fuel pump i'm going to use. I'm looking at the aeromotive A1000 fuel pump and run at around 20 PSI which will make the injectors flow alittle more. But i need to look and see if it is ethanol approved as i want to run E85 after i get it all running and tuned on gas, then i'll program a dual table and be able to toggle back and forth between the setups depending on which gas i fill up with.
It sucks having so many ideas that by the time i go to write them down i start to think about another one and forget about the first one. ou: That and being 20, taking 18 credits at college, working on 2 project cars, and trying do it all on a very tight budget makes things go slow. Plus i seem to have a problem sometimes keeping myself motivated enough to work on my car and then it goes even slower. I've given myself a deadline on my 62, done by may of this year, because i want to enjoy it rather than talk about it. I think i can do it. I have most of the parts, now it's just a matter of putting it togather.
Oh well, enough of the rant for the night.

Thanks,
Jeramie:grin:

 

Very interesting. Nice to see some enginious car crafting by another young person!