1981 P30 Stepvan question about engine swap.

[darkpony02]

I recently bought a 1981 Chevy p30 stepvan with a 454. Which is what led me to this site. I am hoping someone might know if I can yank the 454 out and drop a 305/350 engine in its place.More importantly will the small block bolt up to the current automatic, or is the bellhousing different between the two.The truck is rarely fully loaded, and with the price of gas the 454 is just overkill. I was going to go with a 305 but I dont know if it will be too small, your input would be greatly appreciated.
Thanks.

[chevyguy]

The samll block will bolt right up, You probally have a turbo 400 transmission. This is what makes chevys better than any other, Yes it will bolt right in,You will need to change the exhaust slightly, but other than that is shopuld bolt right in. Try that with a dodge of ford. I dont think so. As for a 305 it will be short on power but if this is a delivery truck or the likes and you dont have to run it 80 down the highway, then a 305 will be fine. i would drop in a cam while you have it out that will help the power drastically. As for fuel mileage I dont know if it will help you out or not, The smaller motor will have to work harder.

[Itstali25]

In MY opinion the 305 is not gunna have enough power, of course it depends on the usage of your vehicle, i have a 305 in my 86 Chevy c-10 and i'm always wanting more power, but thats a 18 year old for ya lol Welcome to truck forums by the way, stop in often!

[chevyguy]

He probally has alot lower gear in the bigger truck too, that makes a difference, You can use a 6 banger if you wanted only in town type driving, but they are notorious for bad mileage. Go with a small v8 if you dont hog on it alot. Let us know what the truck is being used for also, and type of driving.