Hi everyone. I have several questions which the answers will help determine which engine swap I do.

1) is the Aurora 4.0L bell housing bolt pattern the same as the Northstar caddy 4.6L?

2) is the Aurora 4T80 bell housing the same as the 4T60 from a 3.8L powered car?

3) does anyone know if a 4T65HD can be mated to a LS1/LS6 (this is the swap I really want to do...)

sigh,,, so many unknowns...

thx for any help you can offer...

1) Yes
2) Yes
3) Wouldn't know why not, physically, but it's not rated for that much torque

John Stricker

quote Originally posted by cptsnoopy: Hi everyone. I have several questions which the answers will help determine which engine swap I do. 1) is the Aurora 4.0L bell housing bolt pattern the same as the Northstar caddy 4.6L? 2) is the Aurora 4T80 bell housing the same as the 4T60 from a 3.8L powered car? 3) does anyone know if a 4T65HD can be mated to a LS1/LS6 (this is the swap I really want to do...) sigh,,, so many unknowns... thx for any help you can offer...

Thanks jstricker,
+ to you. was not sure about being able to hook up the 4t65HD either to an Aurora 4.0L which a came across or a LS1/LS6 which I would prefer. I was hoping to save weight using the lighter trany and I don't have plans on abusing the power at this time. The way I am beginning to understand it though is one ought to use the 4t80e that comes with the Aurora or a caddy if your not planning on using a stick shift just to get the electrical signals (inputs) that normally go with the Aurora/Northstar ecm. The fear I have with the LS1/LS6 block is that its oil pan may be too wide to fit the 4t65HD or the 4t80e. I was wondering if anyone had tinkered with that idea and knows for sure? I read LS1swaps info but he used a manual tranny.

thanks again