Another 307 Build

[pontiacvince]

I know there's been other 307 builders on here, but I still have to post mine. And I've heard all of the "but a 350 is better" comments. This is the original numbers matching engine in my '71 Suburban. The block was bored +.030, I ordered a CompCams 260H complete kit, .212/.212@.050, .440/.440 lift, a regular Edelbrock Performer with a good Q-jet, and I used a set of #416 305HO heads for better compression and a bigger intake valve (1.72 307 vs. 1.84 305). I switched to a good HEI. I also had a 700r4 built and got a Hughes 1800 torque converter. I'm using the Summit brand 1 1/2" headers, a Summit X-pipe, and the "Quiet" 50-series Flowmasters.

[Mnguy]

The 307 really wakes up with decent heads. That should be plenty of power and get decent mileage with the 700r4 behind it.

[franken]

I would ask why?
If you're building an SBC and not going to DD it, why not go as big as possible vs as small as possible?
Just curious, it's your engine.

[67 twins]

Originally Posted by franken

I would ask why?
If you're building an SBC and not going to DD it, why not go as big as possible vs as small as possible?
Just curious, it's your engine.

As small as possible? There were five factory SBC smaller than the 307. So far cry from as small as possible

[weasel29gm]

Good simple build it's not a race truck, good choice.

[C101972]

The 307 is a great engine! A lot of people don’t give it enough credit, probably because they never had one. I have had a few over the years and with great results. You should have a great drive train, you have made excellent choices for your truck. Thanks Chuck
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[54blackhornet]

My 71 C 20 still has its original 307. It runs great and has never been opened up. I did install a GM HEI. Everyone tells me those engines are junk but I disagree. The truck is used primarily to bring firewood in from my wood lot. It sits all winter afterwards. Starts up every spring religiously…Jack

[special-K]

I have to ask why go as big as possible? The 307 has great characteristics that pick up power very easily while demanding less fuel. And, going big as you can means a 400, not 350.
That cam, better heads, ignition, intake, exhaust will make it another animal. I did one and loved it. I ran a 450cfm Holley spread bore. This was in a '71 K/20 4spd with 37" mud tires. It ran better than a 350 and got 13-14 mpg

[HotWheelsFan]

Curious how the cam was chosen?

I put bigger valves (head swap) on a small sized v-8 in the past and had to change the cam because of that change. I can't remember if I was advised during the work I did or if I had to go back into the engine and do the cam swap afterwards. Was long ago and on an AMC 290 engine. The small engine made for a decent cruiser at highway speeds and was not a gas guzzler like all my other vehicles at the time.

So, my memory fades a bit, and I am not experienced at modifying valve/cam specs, met an engine builder, Jim Grubbs, back then and have used his services ever since for such modifying. I think I remember him stating the duration needed to be changed due to the bigger valves? Just curious as I had gone down a similar road back in the day.

Myself... I like the big engine. However, there is so much more than displacement when it comes to modifying vehicles and I have respect for them all.


Bob

[pontiacvince]

Originally Posted by franken

I would ask why?
If you're building an SBC and not going to DD it, why not go as big as possible vs as small as possible?
Just curious, it's your engine.

Not sure what "DD" is, but as I stated it's the original engine to the Suburban.

I picked the heads because of the 58cc chambers to up the compression, and the 1.84 exhaust valve was bigger than the 1.72 from the 307 head, plus there wouldn't be an issue with bore interference. The cam was chosen because it will be big enough to give a slight performance sound and increase torque for the smaller cube engine, while giving good mileage as well, but not so big I need to get a high stall converter and different gearing. I have changed the factory 21gal. fuel tank to a 40gal. tank because I intend to DRIVE this thing on road trips! Smaller cubes, better mileage, good performance, bigger fuel tank. Smiles per mile!

[LockDoc]

-
DD means "Daily Driver". I think you have a great engine and should have a good driver with it installed....

I have a 305 that has been built with some pretty trick stuff.

305 Engine Specs

1989 1 piece seal block
Balanced
Roller Cam
Hydraulic Roller Lifters
1.6 Roller Rockers
.010, .010, and .030 Over
Scat Rods
Mahle light Weight Graphite Coated Pistons
Low Drag Rings
1978-81 305 Heads, Fully Rebuilt
1.50” & 1.72” Valves
Exhaust Ports Cleaned Up For Smoother Flow
Edelbrock EPS powdercoated intake
Powder coated vintage style valve covers

It was said that this engine was built for fuel efficiency so I'm not sure how the installed parts relate to that but it all sounds good.

I haven't installed it in anything yet but I have been thinking about putting it in my '36 Ford Coupe. It should work good for that.

LockDoc

[697498chevy]

Very nice , my 1969 C 10 has a 307 . Just looked and it has 261,687 on it . Engine has never been out . Think I had the heads rebuilt and prolly changed the cam and lifters . Thanks for sharing !

[pontiacvince]

Doc, do you have the specs on that roller cam?
That sounds like a sweet lil 305!

[jumpsoffrock]

I only know a handfull of people who put giant overbuilt expensive monsters in their cars and drove them.

I know a heck of a lot more people who put giant overbuilt expensive monsters in their cars and let them sit or talked about driving them.


I have all the respect of someone who put a 307 in a truck but actually used the darn thing--for fun or work.
If God gives ya lemons make lemonade--and if you already got a 307, slap 'er together and get on the road.

It's cool to see you sticking with a Qjet.

[LockDoc]

Originally Posted by pontiacvince

Doc, do you have the specs on that roller cam?
That sounds like a sweet lil 305!

Sorry I don't. The engine came with my '72 Chevy Dually but I didn't want to use it in that. I just put it on the engine stand a while back so now I can start it and see what happens. It has never been started.

LockDoc

[pontiacvince]

Originally Posted by jumpsoffrock

I only know a handfull of people who put giant overbuilt expensive monsters in their cars and drove them.

I know a heck of a lot more people who put giant overbuilt expensive monsters in their cars and let them sit or talked about driving them.


I have all the respect of someone who put a 307 in a truck but actually used the darn thing--for fun or work.
If God gives ya lemons make lemonade--and if you already got a 307, slap 'er together and get on the road.

It's cool to see you sticking with a Qjet.

I'm an old Q-jet guy!
https://www.youtube.com/watch?v=ytgZJR6yDOo

[CG]

Sounds like you know what you are doing and you have a game plan.

I'm just curious though why the allegiance to having the "original engine" to your burb when all that is going to be original about it is the basic block casting, and even that has been punched out.

I read your burb thread. Lots of good stuff happening there. I have a 72 C10 Burb myself, just sitting for now.

[HO455]

Looks like a nice engine. Personally I think most of the 307's bad press comes people confusing them with the 305 smog motors that replaced the 307.

With your nice 307 you won't be forced to install a larger fuel tank like you would with a 454.

[674wd]

Nice engine! There's nothing wrong with the 307, It's just a stroked 283 if I'm not mistaken. With the right parts as you are putting on it, the engine should be fine. Ive had one or two over the years and with the right upgrages (parts) they run good.

[674wd]

Also, upgrading to an overdrive transmission was a good idea. I have a 4WD 67 chevy and put a NV 4500 5 speed manual in it to have the overdrive capability. Good luck with the drivetrain combo.

[Warrens69GMC]

That should go down the road well!! Good choice of components!