help with 454 swap

[kyle.rj133]

i know its just another 454 swap but i need help.
i finally decided to get going on my blazer again.

my blazer is a 1986 gmc jimmy and currently has a 305, 700r4, np208 with 10 bolts. and 4 inch skyjacker all suspension lift.

plans: 454 swap(its ethier a late 70's or early 80's) 52/56" swap 14 bolt ff and dana 44 in front

i need a totall run down of everything i need. or could some one point me into the right direction for doing this swap?

questions:
1. will the 700r4 bolt up with the 454?
2. motor mounts?

i will get pictures a.s.a.p. thanks for all the help that i have all ready learn from ck5 members!!

 

[b454rat]

Unbolt the 305, pull, install 454. It will bolt up to your tranny, and the mounts are the same. Accessory stuff is the only difference.

 

[kyle.rj133]

ok sound easy enough. 2 more questions.
1. should i try finding a different radiator? and is the altanator the same?

2. should i really stick with the 700r4? or should i go with something else like sm465, th400? i will mostly be using this a truck as a trail rig hoping to be ready for blazer bash and mudding.

 

[b454rat]

Might want to get a bigger rad, but I used the stock 2 core that was in my truck. Didn't get hot, but was already getting cool outside, might have helped some.

Keeping the 700 is up to you. Heard that a built one will hold up to a big block, but might not be a bad idea to look for something stronger. I loved my truck with 454 4-speed.

 

[kyle.rj133]

ok thanks. i will keep searching around but it doesnt sound as difficult as a thought it was going to be. i will most likly get to motor mounts because it wouldnt hurt.

 

[Wasatch K5]

I swapped in a 454 TBI from a 1988 Suburban into my (previously) carbureted 1986 Blazer with a 350.

I bought a "donor" Suburban and harvested almost everything I needed from that. Since you are going to stay with carburetion that's an easier swap.

I will say it's very nice to have all the accessories, brackets, pulleys, belts, hoses, etc at your disposal rather than making umpteen trips to a salvage yard looking for various parts.

I would recommend you go with a 454 radiator rather than one for a small block. It's Much bigger!

I also went with a 700R4, but I didn't use the one from the Blazer. Here's why:

When GM introduced that transmission it was somewhat "under-engineered" and they had lots of problems. GM upgraded the transmissions quite a bit and IIRC, in 1988 made a number of significant improvements to it. I went with a 1989 GM factory overhauled 700R4 that not only had the improvements from 1988 but all the updates since as well.

Good Luck!

 

[onetonbb74]

you will need a dual bolt pattern flexplate external balance so it bolts to the 700r4, summit sells them.

 

[kyle.rj133]

ok. i didnt really know that they upgraded the transmissions in 88. i just thought that they were always crap. is it possible to go from carbed 454 to tbi?

 

[kyle.rj133]

if i were to go with a sm465 would i still need the different flexplate? maybe i should just stick with a 350? what do you guys think?

i mostly want the truck for muding and camping/hunting trips plus a daily driver and rocks on occasion nothing to serious?

 

[onetonbb74]

for a stick, you need a flywheel, flexplates are for automatics and the bolt pattern on a 700r4 is a differnt diameter circle then th350/400 trans that usually comes behind the 454.

 

[kyle.rj133]

ok. thanks a bunch!!! so do you think i should stay with the 454? becuase i can get a rebuilt 350 for about the price im going to be spending on the 454. im just not sure if a 350 will satisfy me?

 

[76zimmer]

Well if you get a 454, and you use that power much, you'll be finding your weak links...that otherwise might be ok with a 350. Then again if you get a hp 350 you'll be finding some too. I just think that a BBC will find em quicker.

 

[kyle.rj133]

ok i will probably just stick with a 350 for now and then when more money comes start building a 454 thanks for all the help