all you guys that went big block was it worth it?

[Heavy Evy]

I have been debating on going big block in my 71 C20 for awhile now. I have had some good deals come and go but never jumped on any of them. I love my 350 it will never let me down but I want the lowend just incase I want to get a boat or somethng to tow also the power would be great too so I could move my 5000 pound hulk around a little bit faster haha. So im asking was it worth it in terms of work like changing motor mounts pulleys high hump etc and performance wise. Let me know fellas.

[pulltilbroke]

I started out with a mild 350 in this truck but after it popped I went with a mild 462 and never looked back. I don't care to own another small block.

[hotrod farm truck]

Absolutely,and still have the low hump

[Hottrucks]

OH YEA!!!!!!!!!!!!!!!!!!!!! 2 days by myself for a 500 caddy swap it was cake and bolted right in

[DANTIP]

After re-reading your post I am confident you would like the low-end torque of a big block. The biggest difference in my opinion is right out of the hole. Oval-port heads/intake on a big block give it excellent low-end performance that is ideal for a heavy/tow vehicle. I had a ZZ3 small block in a SWB truck and loved it but it didn't feel as strong under 2000 rpm.

[406 Q-ship]

If you want lowend without the swap to Big Block......let me say 400 Samll Block. Big torque of a Big Block in the package of a Small Block.

[Shyguy]

A big block will definitely give you the torque you want but there are a few draw-backs to doing it. We put a 73 454 in my '71 with a granny 4 speed that was mostly stock except for the cam and headers and I really noticed the difference over the stock 350.

A low hump cab will work with an auto or 3 speed. My son has put big blocks in three of his trucks with the low hump and it worked out ok. Two of them had the three speed manual and one a 350 auto.

Here are some things that will help I hope. A 700R4 would be good behind it with 3.73 rear gears, but if you are running a 350 aut use gears more like 3.08.

Go with a mini starter if you are running headers. A 3 core radiator will work ok unless you are also run a/c.

More torque will mean less mpg, but you will be able to tow anything you want to.

If you are going to tow 5000 pounds are so it is nice to have heavier rear springs or air shocks or the auxiliary over-loads.

My son is running a 402 in his '72 with a 350 auto and 3.08 and likes it real well, except for the worse mpg, lol.

[72chevyk10]

Originally Posted by Shyguy

More torque will mean less mpg

may i ask how? i thought more torque would get better mpg..? engine doesnt have to work as hard. horsepower is what takes the mileage

[pulltilbroke]

Originally Posted by Shyguy

My son is running a 402 in his '72 with a 350 auto and 3.08 and likes it real well, except for the worse mpg, lol.

When I swapped my mileage stayed the same

[LockDoc]

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I have a big block in the White '67 and a big block in the Blue '67 beater. I enjoy driving both of them. I changed the rear in the White truck to a 3.07 and it made it a lot nicer to drive.

LockDoc

[Heavy Evy]

my 71 c20 is built to tow. the leaf springs are huge and have over loads as well. it has a th350 trans and a dana 60 with 3.54 gears. it had 4.10's but they sucked on the freeway. it will tow 5000 pounds right now no problem im just saying it weighs 5000 pounds. no go on a 400 sbc ive had a few and they always blow up. i had a 383 which did good in my truck but it was built for racing so i swapped it in my nova. thanks for the all input and advice gentlemen.
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[RCbowtie69]

I had both & love both of them,it's what you need to do with the truck,pull or just drive & go fast,oh that's both of them,it's a Chevrolet & that's all good

[Dave]

I've used SBC and BBC engines in all the 69-72s I owned and I have to say hands down the BBC 402s and 454s offer more towing benefits "out-of-the-box" over the SBC's.

Even though BBCs do tend to be more expensive to operate (mpg), among other things, nothing beats the deep tone sound and low end performance these engines produce.

[72chevyk10]

i actually get a LOT better mpg with my 454 then i ever could get out of the 350 that came with the truck.. the 350 would only get about 3-4. this 454 (after about 2 years of tuning) will get 12-14 if i stay off the freeway. on freeway its about 8. it doesnt like to wind up very high very long but through town with the 4.10 gears it does great!

[ItsRandy]

Once you go big block you'll never go back! Yes, worth all the work and every penny.

[pulltilbroke]

And they look so much cooler.

[stich626]

depends, is this a week end toy..
bbc are fun but if you can't feed it, and you park it, it's pointless.

[mustardjimmy71]

nice cal customs valve covers

[pulltilbroke]

Originally Posted by mustardjimmy71

nice cal customs valve covers

Yeah, those were an awesome swapmeet score, IIRC I spent 40 bucks on those.

[leddzepp]

yes
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[FRENCHBLUE72]

I went bbc and love it even though I have never driven it down the road yet..

[Heavy Evy]

i know alot of guys getting the same or better mileage than a sbc. its all in how you drive and tune it. 10 plus mpg and im happy.
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[bobs409]

all you guys that went big block was it worth it?

I'll let you know as soon as the gas prices ease up. I have a fresh 454 I put together over the winter for my 69 stepside but have decided to hold off the install for now. Will have to run premium and with the current gas price nightmare, I don't feel too inspired at the moment.

Maybe by fall...

[VA72C10]

I'm excited to hear my 402 fire up for the first time

[Ole Greenie]

Worth it? Well, yes and no...

Yes, because I have not seen another truck with an LS6. It is pretty sweet with possibly the only LS6 powered 67-72. Although I have a 700R4 and 3.08 gears, the best I've had was about 14 mpg.

No, because it really likes to drink. If I had to do it over again, I would have waited and placed a 6.0L or 6.2L LSX motor in it. Excellent power at 24 mpg.

It all adds up to personal preferrence. I wanted something really cool and nostalgic. When I swapped the motor in 1999, gas was about $1.20/gal. 11 years later and about 5000 miles on the motor, she will be driven weekly but daily. Keep in mind, it takes 93 octane.