904 for 408?

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74valiant

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i have a 408 stroker that is going in my valiant. i originally planned on a stock 360 but as usual things got out of hand. the 904 that i bought for the 360 is a brand new rebuild. not sure on the specs, but the trans guy i bought it from said it was stronger than the stock 318 904. im just wondering with the durastic change in horsepower whether the trans will work in this configuration. i still have the original 904 bolted to the 318 and can rebuild that if needed. i would also consider other transmissions with more gears. gotta be pretty close to bolt in though as i dont want to do any crazy mods. any advice?

the car is a 4dr fully loaded up, and will see mostly street use. 408, with 8 3/4 rear with undecided rear gear.


im also debating what a good rear gear size would be
 
904 should be alright in the light body. Just put a stage 2 shift kit in it and appropriate gearing.
 
the 408 is nothing crazy. It has a scat rotating assembly which I believe is 9 and a half or 10 to 1. Comp cams xe 268h cam and lifter set. J heads with 1.88 and 2.02 valves and minor porting work. I was told it should be around 425 horsepower and 450 to 500 ftlbs of torque. will the tf2 kit make the transmission shift harder? Or any transmission shift kit for that matter? The car is going to be given to my parents and I don't want it to drive to crazy
 
74valiant said:
the 408 is nothing crazy. It has a scat rotating assembly which I believe is 9 and a half or 10 to 1. Comp cams xe 268h cam and lifter set. J heads with 1.88 and 2.02 valves and minor porting work. I was told it should be around 425 horsepower and 450 to 500 ftlbs of torque. will the tf2 kit make the transmission shift harder? Or any transmission shift kit for that matter? The car is going to be given to my parents and I don't want it to drive to crazy
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That there is funny,thanks for the laugh.:happy2:
The TF2 kit will give firmer shifts,but nothing to crazy without swapping the torque convertor.
 
Whats Funny?? I was told by the engine builder to run about a 2800 stall also.any idea on what would be a good streetable gear for this? I have a few 3.23 suregrips, one of which I could swap gear ratios
 
74valiant said:
Whats Funny?? I was told by the engine builder to run about a 2800 stall also.any idea on what would be a good streetable gear for this? I have a few 3.23 suregrips, one of which I could swap gear ratios
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Whats funny?The part where you say nothing to crazy as my parents will be driving the car.Maybe just me,but the 408 in these small cars is slow car.JMO the 3.23 should be fine.
 
make sure you tell him you want a 2800 stall behind a 408....as the engines get bigger...the converter will flasher higher due to the increase torque to the torque converter
 
Drag guys run 904's in 727 cases. They are strong enough if built right. I think a TF-2 904 will be fine, it is a light car. I wouldnt put one in a C body.
 
74valiant said:
Whats Funny?? I was told by the engine builder to run about a 2800 stall also.any idea on what would be a good streetable gear for this? I have a few 3.23 suregrips, one of which I could swap gear ratios
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I HAVE A 408 STROKER 3:91 REAR 904 TRANS.. 4000 STALL CONVERTER..

the car is streetable.. and alot of fun...
 
Your parents will hate the car because of the fuel milage and having to run premium gas. Make sure they don't trade it in for better gas milage.
 
airwoofer said:
Your parents will hate the car because of the fuel milage and having to run premium gas. Make sure they don't trade it in for better gas milage.
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haha... i dont think they will be driving it to much. itll be a nice weather car. i really didnt expect to go this far with it, but the bigger the better right? im also making a portfolio for job advancement from the car so theres more than one objective for this. along with the motor, its also getting a 2 tone interior, custom rotisserie paint job, custom stereo, along with new EVERYTHING





p.s. i can gaurantee my parents are gonna keep it. just the way they are
 
The Trans-go TF-2 kit is a great kit and will make it shift firmer but it won't make it shift real hard but since it's for your parents you might want to just use the TF-1 kit. I haven't used it but it's supposed to be milder. Considering the driving style (not being raced and no crazy hp) the 904 will due just fine with a mild shift kit. 3.23's should work good unless your running a real short 14" tire in which case you might want to consider using a 2.76 or 2.94 gear. When you decide what gear you will run give all the specs to a good converter company and have one made specific for the application. Will work much much better than an off the shelf converter. Sounds like it will be a real neat sleeper when your done.
 
thanks for the help guys! I do have a few pics but the car is only disassembled right now. Haven't really been able to get much done besides buy parts. I've been waiting on painting the car due to not finding a reputable painter who will paint the car within a reasonable price nevertheless have a paint booth large enough for rotisserie. I'll be posting pics up as the car gets assembled but that won't be till after this winter
 
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