I am looking at building up a 400sbc for my '88. My question is, I have a 305/TH350 combo in it already, will the TH350 be strong enough to handle the torque and HP that this motor can produce?

 

Yup.

 

It depends on many factors like the HP of the 400 to start with.

 

I'm assuming its pretty much stock...

 

It is going to start out that way.. I am sorry that I was so vague. I have looked into the combo and its not so far fetched. I have hundreds of options and I have explained nothing. Sorry ...

 

Well stock for stock, that 400 made less power than your 305.

 

400 Production: 1970–1981 Displacement: 400 cu in (6.6 L) Power: 150 hp (112 kW)-265 hp (198 kW) Bore and Stroke: 4.125 in × 3.75 in (104.8 mm × 95.2

305 Production: 1976–1992 Displacement: 305 cu in (5 L) Power: 130 hp (97 kW)-250 hp (186 kW) Bore and Stroke: 3.736 in × 3.48 in (94.9 mm × 88.4 mm)

 

And the 305 in my Camaro is a 1977 LG-3 4-bbl.... I can get a lot more power out of that 400 than I could ever get out of that 305... I do have a 1992 TBI 305 out of a Trans Am that I will be useing till I rebuild the 400.. I will be looking into what I want to build up the 400 to soon after breaking it down and getting it ready to be machined ...

 

I am also looking at another '88 RS to dump the TBI 305CiD into till I am all ready for the 400. We will see by the end of the summer which puts out more power ;-)

 

There is little to debate over which motor holds more potential power. With the right heads and cam the 400 will kill anything the 305 can do.

 

I guess I will use the TH350 till I can build a new tranny for it ..