BBC into a 86 SWB

[68longhorn]

I have a 1986 C10 SWB with a 305/700R4 that is my daily driver. The motor is tired and a 305 so I'd like it to go. A friend has a 454 from a 80s Suburban for sale at a good price. What all is needed to swap in the 454? Will motor mounts, accesories, exhaust y pipe, etc bolt up? (I only ask about the exhaust because I need the install to look factory) Will the valve covers clear the A/C case? I've swapped plenty of small blocks but this woulb be my first big block so I need a little info.

[Sniper X]

I was told yesterday, by a guy I know who did that same swap, that everything bolts up no problem. He was answering my same basic question, about putting the 454 from my 78 into my 74. But the tired part is the other way round for me, the 454 needs the heads to be rebuilt so I think Ill do the whole motor then swap it in this winter.

[68longhorn]

Really that easy? I was expecting a list of snags. lol

[454HO]

Sorry to burst your bubble, but while it is not a difficult swap, it ain't a cake walk either.

The big block will tear up that 700r4 in short order unless it was rebuilt to handle the torque. You will also need a heavy duty 4-core radiator if you don't already have one. And no, the 305 exhaust Y-pipe will not just bolt up to the BB manifolds. The engine stands and mounts will bolt right up, no problem there. Clearance with the a/c box and the brake booster is not an issue. If it is an all iron BB, then expect the front end to be an inch or so lower. If it has an aluminum intake, that will help a bit.

It is a bit of work, but if you plan everything out you can do the swap in one weekend. And I assure you, it will put a smile on your face the first test drive.

[ortega]

i just swapped my v6 in my 85 for a 454 out of an 89. it was i bit more work but not bad. my biggest issues were the driveshaft being to short, and the wiring on the engine. and its a lot more fun to drive..

[68longhorn]

That sounds more like what I was expecting. lol

[ont_guy_38]

did that swap in a 1978 once and remember i had to lengthen most of the wiring.Used headers but ya 454HO is correct the y pipe will not bolt up

[Sniper X]

When I do my 454 swap into the 74 I am going to use headers and duals. With a H pipe.

[grinch4om]

I did it am driving it now. I also had the complete suburban(wreck down the side) for all the mounts, brackets and do dads. used headers and duals, aluminum intake, dropped the nose 1.5 inches.all wires worked I did have to make and create a/c brackets but if you use the donor vehicles compressor(if they are different, I wanted the smaller one) it is all a bolt in

[spaseghost]

wires are easy to splice/lengthen if you do it right. the front end sits a little lower, upgrade tranny (replace or rebuild), different driveshaft, and alot more gas... junkyard 454 radiator, works fine in the desert for me. i dont have an a/c compressor or condenser abymore, that dont make it faster anyway.

[grinch4om]

I didn't have to lengthen any wires. I did however destroy the tranny and thusly built an 89 700 r4 out of a Camaro to live behind the rat. I didn't use the 400 turbo because I wanted the overdrive. Used the same driveshaft as the 305/700 used...I am scared though that if this thing ever hooks, it will pass me...

[munice]

You guys are saying the motor mounts bolt right up... are you saying that you can drop the big block onto the small block mounts? (I have a 350 ci) or do you need new mounts from the donor truck but they'll bolt into where the small block mounts are?

[b454rat]

I did plenty of SBC to BBC and never changed the mounts. I just did my old 84 that was a 350/700 to a 454 4-speed, didn't change the mounts. I even used the stock SBC radiator, but also have a huge oil pan to keep the heat down. I used headers off a Chevelle, they fit OK, but were close in some spots. I liked them cause they tucked the exhaust up in the frame instead of hanging below it, possibly getting caught on something while wheeling.

[munice]

OK, Thanks! Im considering building a 454 myself, but looking to run TBI still

[munice]

the other question I had about a conversion like this is what would i need for mating the 454 to my SM465? its in a 4wd truck

[b454rat]

Just the 454 flywheel. When I did my swap all my stuff came off a small block truck. SBC and BBC share the same bell pattern.