How much motor do I need?


#1

I’m getting ready to build a new motor for my truck, which is a 77’ Chevy pickup (250 c.i. inline six w/TH350). This last summer I used it to tow a 3000-4000lb boat, which It pulled fine on the freeway, but as soon as I start climbing into the mountains I’m down to 2nd gear going 35mph. I need more power. A friend of mine has two blocks, a 327 and a 454. It would save me a lot of money to use one of these blocks, but I fear that the 327 might not be enough, and the 454 might be too much. This truck is a daily driver, so fuel use is a concern. Or is the trusty old 350 still the best option?


#2

The 327 should have MORE then enough power. Also a very very durable engine. I tow 3k with my Toyota 4.0L V6 without any problems. Even on hills I’m only down to 4th (5-speed auto).

If you can…look at replacing the carb with a FI system. Holly use to make one for all the GM V-8’s. I did one once and it made a hugh difference in performance an gas mileage or the stock Quadrojet.


#3

Yes, the 327 should be fine, if it’s in good shape, no need for a 454 for 4000 lbs. Not much difference with the 350 vs a 327.


#4

Just what I needed to hear, thanks guys


#5

I would say it depends on the defintion of the word “block” as you’re using it.
Block only, good long block, long block that needs to be rebuilt etc.

If this process involves building an engine and/or rounding up parts to complete an engine then I’d say just find a complete running 350 since they’re plentiful and cheap.


#6

I agree that a complete block would be best and depending on condition of both engines he has.
I’d personally go after a 350 if neither are in good condition. For extra performance, a stroker kit could be added to it


#7

When in doubt go big. If you can get the 454 for a song, go with that. Otherwise the 350 should be fine as well. There is no such thing as too much motor.


#8

There is when you worry about fuel mileage. 454’s are thirsty engines.


#9

Both the motors are low mileage rebuilds. I’m looking at doing a basic rebuild. Both motors are complete so I will only have to worry about the mounts and exhaust, which brings up another question. Do I have to make motor mounts or can I just get Chevy small block mounts and bolt on?


#10

The 292 would be the easiest and likely the cheapest upgrade.


#11

There’s no replacement . . . for displacement! Sorry, never got the chance to use that one. Seriously, look for a good 350 . . . there’s a lot of them around. Rocketman


#12

You might need the 4 speed or a 3.90 rear axle ratio.