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k5 Blazer 350 to 454 swap

7

76BLZR

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Hello all,

I have a 76 K5 blazer 4x4 manual transmission. I've swapped the 350 with a 454. Now I've read every post and watched every video I could find with some helpful info, but nothing that has helped with this issue.

I read a post that side the 350 and 454 engine brackets are different. I tried installing the engine with the 454 brackets. That didn't work due to alignment issues, so I bought 350 brackets with the same results. Now comparing the two brackets side by side they looked almost the same. Not much of a difference between the two.1.jpg2.jpg

The problem is one side the motor mount bolt holes will line up. But the other side the motor mount sits an inch above the crossmember holes. Its like the motor is to wide for the crossmember. Everything I've read say the 454 will drop right in with all stock 350 mounts. Also I've read the clearance between the oil pan and crossmember is close. I have just under an 1.5" of clearance. So that is telling me the engine is sitting higher then it should. I just can't figure out the issue at this point without just buying a bunch of parts to see what works.

Look at the pics tell me what you guys think.passenger .jpgDriver.jpg
 
I used the ORD HD crossmember with the comp motor mounts on my 454 swap.
 
So you guys had no alignment issue at all with the ORD mount?
 
Or do this and dont think about it again.

www.offroaddesign.com

Big Block Motor Mount and Crossmember Combo Kit for 73-91 GM/Chevy Full-Size

Combination Kit of Competition Style Motor Mounts for 73-87 GM with Big Block High Clearance Engine Crossmember Big Block, 6.2L Diesel and Gen III/IV GM V8 Applications Stiffens the frame, increased crossover/high steer clearance, eliminates weak factory crossmember. Includes competition style...
www.offroaddesign.com www.offroaddesign.com
 
You should be able to swap using the stock brackets but I am not sure why yours are not lining up.
 
76BLZR said:
So you guys had no alignment issue at all with the ORD mount?
Click to expand...

Yep, you can expect to have to make it line up. These frames move around a lot without considering that most are 50 years old.

Pull the tcase crossmember and then put it back, it’ll do the same thing.
 
Warning, when you swap that engine crossmember the frame rails will spread. A ratchet strap will help pull everything back together.
 
Pretty sure there are also car engine mounts. Maybe truck to truck are the same, but here's a pic I took many years back when we were swapping a 454 into my dad's truck.

Which is which has been lost to the ether of time. But clearly all motor mount hats are not the same.

full
 
nvrenuf said:
Warning, when you swap that engine crossmember the frame rails will spread. A ratchet strap will help pull everything back together.
Click to expand...
I did not have to use a strap but I did leave all the bolts finger tight until the engine was in place. Once the engine was mounted I tightened up all the bolts. I was worried about the alignment of the rubber mounts the first time.
The ORD kit is real stout, I think you will like it with that big motor.
 
76BLZR said:
Thank you guys. I'll get it ordered.
Click to expand...
I could not get my 454 to fit with fabricated valve covers. I had to switch back to some stamped chrome ones to clear the brake booster. What booster are you using? looks like you clear big valve covers.
 
HankScorpio said:
I could not get my 454 to fit with fabricated valve covers. I had to switch back to some stamped chrome ones to clear the brake booster. What booster are you using? looks like you clear big valve covers.
Click to expand...
They are from Ansen. I had to remove the valve cover, loosen the booster and pull it over to slip the cover in. Once the motor is sitting where it should. There will be more clearance. Right now it's about a 1/2" of clearance. Thats not enough, once the motor torques over it will hit.
 
HankScorpio said:
I could not get my 454 to fit with fabricated valve covers. I had to switch back to some stamped chrome ones to clear the brake booster. What booster are you using? looks like you clear big valve covers.
Click to expand...

I realize all fabricated covers aren’t the same but my eBay specials fit with the original booster on my ‘91.
 
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