The Stovebolt Site Forums The Shop Area Engine Shop MORE POWER - 305 - 454 Swap, will it work?

I've been thinking about picking up an 80s or 90s pick-up truck 4-bolt 454 (probably not a tall-deck) for my 1968 C60...would this engine directly bolt into place with the existing smallblack (305) mounts? If not, what kind of fabrication or parts buying can I expect to do? I'm short on cash and skill, and praying for a pretty direct bolt-on.

You'll need a different (as in BIGGER) radiator, ditto on the exhaust system. None of the accessory brackets like power steering, alternator, etc., from the 305 will fit, so get everything you can from the donor vehicle. Bellhousing bolt pattern will be the same, not sure about motor mount brackets. You might need a torque converter with a different stall speed, assuming the truck has an automatic trans. The big block will pull a lot harder at low speed, so a lower stall speed converter will make it work better. If it's a C-60, it's probably a stick shift, but if you can get a Turbo 400 with the engine, drop them both in there!
Jerry

Remember that the 454 is externally balanced. It requires a 454 specific flex plate or clutch disk.

That '68 didn't come stock with a 305. Could it have been a 366 or 427? If so the existing raditor could be big enough.

Also, if anything was butchered to put the 305 in, you may have to correct some issues before putting a new motor in. Otherwise a big block was available in a '68 so stock mounts will be available if the existing ones aren't right.

the previous owner put a new 305 rebuild in, so that explains the incongruous motor. I'm not worried about the accessory brackets and radiator so much as the actual engine-to-frame mounts, but it's good to know about the external balancing...are there any internally balanced big blocks? I would prefer a 366 or 427 tall deck truck engine, but they're harder to come by it seems. The radiator is definitely too small for a big block. It's a Spicer 5-speed by the way.

The smaller big block motors were internally balanced. The 454 is externally balanced. I don't know about the bigger big blocks, but would guess they are externally balanced for the same reasons the 454 is.

If you plan to stay with that 5-speed you would need the correct flywheel for a 454.

My thought of the tall vs standard deck motors is that 454s are the most common and therefore least expensive to build of all the big blocks. The tall deck motors are least popular but perhaps cheapest to buy, provided you can find one.

If I was short on money & skills I would put in a 350 small block. It,s a simple bolt in useing all your presant parts. We ran them in c50s & c60s for years. They pull good & are easier to maintain than a big block.

that's not a bad idea about the 350...I was thinking of maybe trying to get a 4-bolt main 400 smallblock. I love a good 350 as much as the next gut, but I feel like I need a serious cubic inches bonus to justify doing a motor swap in this rig. I'm also trying to avoid even having to build a motor, just hoping to find an ebay or junker that runs well enough as is

The 400 small block is another externally balanced motor.

And they are not easy to find. They are not cheap and finding one a used one in a wrecking yard may be impossible.

A 383 stroker crate motor might be good compromise.

I WENT FROM A SMALLBLOCK 350 TO A BIGBLOCK 454 IN MY 67C10 AND THE ENGINE MOUNTS WORKED PERFECTLY.