Chevy Tri Five Forum banner

1 - 6 of 6 Posts

·
Registered
Joined
·
37 Posts
Discussion Starter · #1 ·
New to trifives and have several questions.

Have a 56 six banger with 3 speed on floor and std rear end/leaf springs etc.

Was going with 502 but it may go to Daytona in its present home and not come back.

Did they go to side mounts in 55-57 or did that start in 58 (several people here arguing). I thought they had front or side mounts starting in 55. Is that right?

Can you use the front and rear mounts present to install a 70-mid80s SBC/350TH or do you have to use side mounts and crossmember for either 350/400TH or Saginaw/Muncie with the SBC?

What HP/Torque is safe to run thru the original 3sp and rear end for non-racing; ie nothing but rolling on the power with no drivetrain abuse? What is the normally accepted area of power to start beefing up the crossmember and changing the rear to Ford 9", Chevy 12 bolt etc?

Will the stock six banger bell housing work with the SBC? This is the one I really want answered....there aren't any good natured bets on this one.

If you use side mounts and crossmember can you bolt in the SBC/350TH without shortening the stock/present driveshaft assuming changing to necessary output shaft?

Who is going to win the WVA-Pitt game. :)

Thanks for your time.
 

·
Registered
Joined
·
4,668 Posts
In the 55 through 57's they used 2 front mounts in conjunction with 2 mounts at the front of the bellhousing. 58 and newer have the side mounts although the front mount holes are still cast into the blocks. The side mounts and the rear trans mount should be used together. The front mounts and bellhousing mounts used together. Some may argue that you can use the front mounts with just the rear trans mount. There are only 6 3/8" bolts holding the trans to the engine and there would be tremendous strain put on these bolts and on the bolt bosses causing breakage of the bellhousing or engine block or both. This is just my opinion as a mechanic of 35 years.
Dave
 

·
Registered
Joined
·
1,670 Posts
I have to agree with Dave, you should not mix the mounts, use either side and crossmember mounts or front and bellhousing mounts. If you are planning to run HEI dist. or BBC, you need to use the kit that moves the engine 3/4 forward to clear firewall without having yo get out the sledge hammer
 

·
Senior Member 4 Gold Stars
Joined
·
4,460 Posts
I put a 409 in a 55 once many moons ago. I set the engine using the original rear mounts and then drilled the crossmember forward for the front mounts. It held fine.
I agree as well that if you use front mounts, use bell housing mounts.
 

·
Registered
Joined
·
37 Posts
Discussion Starter · #6 ·
they make adaptor mount kits to use an automatic with the front mounts and also use a crossmember if you don't feel like welding in the side mounts. You can run the 4 speed using the stock bell housing without the crossmember.

I've gotten all kind of answers talking to people and you see what I got here.

I know what can happen with too much torque using only front mounts and bellhousing mounts as well as front using the crossmember. I don't know what the guesstimate is for torque using the front and rear or front and crossmember. There should be a threshold you have to cross to break the weakest link. I've seen engines tear mounts out. They'll even twist frames chained in.

I also don't know the guesstimate on using that saginaw 3 sp that came in the trifives. The rear will take a fair amount obviously some being stronger than others. People ran pretty stout 327s in the day with those rears. Of course tires were a lot different then and that's IMO what makes or breaks a lot of rears and trannys. JMO.

I think for just cruising you can use the front and rear with a low output SBC but again JMO. I wanted to hear from you guys though as my opinion is not worth a lot to answer my own questions. :)
 
1 - 6 of 6 Posts
Top