454 engine swap

[shannon kaufman]

Hello i just got a 454 for my 70 chevy it has a 307 in it what will i need to look for when i get ready to put the 454 in thanks for any replies thanks shannon

[RACINJASON22]

Not real sure myself but I'm thinking engine mounts(towers), ofcourse brackets for the mounting of the alt. power steering ac if equip. well all the pulley stuff you get the picture and exaust. I have never done this conversion on one of these trucks so I can't give ya any of those helpful hints but I'm sure some one here will know some. ttt

[AKChevyman]

Check the FAQ that is where I got my info for the swap. But pretty much what racinjason said

[454_72_4X4]

The motor mounts will work fine, but you'll need all the brackets for the PS ans alt, and AC if your truck has it.
Also you'll need the BB exhaust manifolds.

Is your truck 2wd or 4x4?

[shannon kaufman]

thanks for the response it is a 2 wd

[Frizzle Fry]

The motor mount towers are different, but you can use the small block rubber pads as is described by Tx Firefighter here. I did this on my 476 install and it works great. I wasn't able to find the thick "harmonic-balancer" type washers he describes so I used four big "body washers" on each side.

[VA_short_67]

On the brackets, make sure you know if you have or going to use a long or short water pump. If you run into problems with brackets, Alan Grove makes multiple brackets. Helped me out when putting power steering in my 67 big block.

[mnunn454]

Exhaust of course will be different, and I think probably the torque converter and the converter cover, and the starter as well.

[454_72_4X4]

Originally Posted by Frizzle Fry

The motor mount towers are different, but you can use the small block rubber pads as is described by Tx Firefighter here. I did this on my 476 install and it works great. I wasn't able to find the thick "harmonic-balancer" type washers he describes so I used four big "body washers" on each side.

The original BB towers are different than the SB towers but the difference is for exhaust manifold clearance. If ya get the "right", (read, not original), oxhaust manifolds the SB towers will work fine.
The rubber mounts are the same also, (although a very weak design).

SB and BB Chevy engines share the exact same motor mount and bellhousing dimensions.

The 454 in my 72 has been sitting on the original SB towers for probably close to 10 years now.
A couple years ago the left manifold cracked and I couldn't find a replacement, (for a reasonable price anyway), and finally broke down and modified the left mount tower to clear a manifold a friend gave me.

[Stoney]

So a big block will clear the bottom half of the firewall? I thought the tranny would hit.

[454_72_4X4]

Originally Posted by Stoney

So a big block will clear the bottom half of the firewall? I thought the tranny would hit.

The transmission will be in the exact same spot as it was with a SB, (unles you move the mounts...)

Clearing the firewall is another story.
First it depends on where your motor was mounted originally. Some are mounted farher forward than others.
BB's were mounted in the "forward" position from the factory I'm pretty sure.

I had to "clearance" the firewall for the rear part of the right valve cover and a little on the left side also, but I can't remember what exactly was hitting.

Clutch linkage is an adventure all it's own if your running a manual trans.

[combustion]

Originally Posted by shannon kaufman

Hello i just got a 454 for my 70 chevy it has a 307 in it what will i need to look for when i get ready to put the 454 in thanks for any replies thanks shannon

well what i did was removed the towers, installed the rubber pads from the the sb to the bb, then modified the brakets to clear the exhoust and place the engine properly. all i did was bolt the engine to the tranny and lay it down with the towers attached to the mounts and observed where the towers needed to be cut and moodifed for the engine to sit right and went on from there. i used a gen 5 motor, so i had to get a flexplate that was balanced according to gen 5 specs and that had dual bolt paterns so it would be able to fit my torque converter since i was using the stock th350. along with that i had to get a bb starer because the flexplate i bought was bigger (168 tooth) than the 153 tooth flexplate you currently have. thasd about all you need to swap it. pt\retty simple swap. here is a pic so you can see how the engine sits

the picture might be not as great, i took it with my blackberry

[mnunn454]

I believe my 69 came with a 307/Pwr Glide originally. It now has a 454/TH400. There's no evidence of firewall interference or modification. There's at least an inch or two between the heads/valve covers and the firewall.