can i make a th350 work in a 2003

[cjcalhoun]

ok what would it take to make a th350 work in a 2003 rcsb.

[tanz45]

yes, but better go 400r

5 out of 6 bolts match up
flexplate spacer
and speedo kit

[cjcalhoun]

well i have a th350 with a 9" converter already was just wondering what all it takes to do it. ive seen flexplates for the ls1 so u can mount the th350 and converter to it just wondering what my options are since i already have the tranny

[mean05]

it's not worth that effort to swap it...your best bet is just go with a 80e...take advice from someone who has already done this swap

[cjcalhoun]

ok just seeing my options why didnt it work out for u

[mean05]

cruising rpm sucks...kills gas big time, the cost of the swap to a th400 was equal to that of a swap to a 80e and the 80e was easier to do and can be controlled by the pcm still

[cjcalhoun]

ive already got the trans. running 3.42 gears and can get just about any driveshaft i need for almost nothing

[mean05]

3.42 gears will put you at about 3200rpm at 70mph. You can get you a DS made to fit it no problem

[cjcalhoun]

ya did the math on the gearing with my tires it showed around 2800 prolly just build the 4l60

[mean05]

yeah im not trying to guide you the wrong way but if you have it all apart and have a little time to build it up find you a good 80e core for around $500 and have a rebuild with a shift kit prob for around another $700 and you'll have a trans that'll outlast a 60e/th350.