I think all SBC's are good just some are better than others, I've just had no experiance with a 307. I'd like to know a lil about them performance wise and history wise(years and applications). I do know they use a large jornal crank that is a cast version of a 68-69 327 crank but thats as far as my knowledge about them goes. Are they torquey bitches or just plain dogs? -Jesse
the 307 isn't a bad motor, but its not known for there speed!!They area torque-y motor & where great in big chevies & wagons. Go to www.mortec.com & they have all the specs on SBC & they can answer alot of questions also JimV
20mpg is a gas hog!?!? that's what i got out of mine... 68 chevelle, qjet, 400turbo..... ran decent but it was a stock rebuild....
They're a good "interim" engine to use while you're building your "real" engine. I had one in a 72 nova once. I slid in a 350 hp cam and bolted on a Q-jet. Ran ok, I guess but was not a wailer.
oh hell, i thought he just had a line on a good one. i'd never build one, 350's are a bunch cheaper to build and'll make more power.. i'd STILL rather have a 307 than a 305... 302'd be better
The 307 was a replacement base engine for the 283. It was never offered as anything but a garden variety econo-motor from the factory. Produced in the late 60s and early 70s, they can be found in all types of cars of the era. The biggest flaw with the factory 307 engines was the fact that the camshafts were not hardened, a cost-cutting move by GM. This caused most of them to wipe out cams rather quickly, making the motors sluggish gas pigs! A simple cam swap will make a decent motor out of your 307, and they accept all the small block Chevy intakes, headers, distributors, etc for bolt-on performance upgrades. As for the 307 vs 305? It's no contest! The 305 is just a small bore 350 (same stroke, smaller bore) and it's a midrange monster that will smoke a 307 any day! The 305 needs a mild dual pattern cam (square pattern cams don't belong in ANYTHING really!) with an .050" duration of about 222 degrees on the intake side and a moderate amount of lift in the .450" area. They make GREAT supercharged street engines, too. I've run several 305s with carefully selected bolt-on parts, and they deliver excellent street performance and VERY impressive fuel economy! The 'secret' for a strong running daily driver is to use the TRW 350 replacement cam (part #274) in a 305 with a Performer intake, 600cfm Holley, recurved HEI distributor and headers. This combination deliverd 14.89 ETs and 24mpg highway in a hefty 77 Malibu for me with stock tranny and rear gears! TONS of torque and RIGHT NOW throttle response! But, back to the 307....it can make for a decent motor to power your mild streeter or daily driver, so long as the factory cam has been replaced! (That TRW cam works okay in a 307, too...but doesn't deliver the midrange pull that you'll get from a 305).
not high on my list of motors. but if anyone wants a 25 buck 307 there is one complete sitting in the corner of my garage if someone wants it. from a 72 chevelle and takers
the are fine when the cam and lifters are replaced- Id bore it to 4" and make a 327 from that basis and then pitch it next time it needed overhauled.....
met a fella at a car show with a 307 in his 70ish Chevelle wagon. He was pulling a solid 600hp on the dyno with it. Single turbo (no intercooler) in a blow-through arangement. Motor was stock on the bottom-end, but the heads were pocket ported and o-ringed to hold the 25-pounds of boost. Mild turbo cam, dual-plane 4bbl intake, and modified headers finished it off I believe. Interesting motor, to say the least.
The only 307 that I had was the one I put into a 74 Chevy LUV truck. Had a 350 tranny and a 9" rear end. Was great for pulling my dune buggy back and forth to the desert but I wouldn't build one today. We always called em "smog motors" here in SoCal because that was what GM put out at the time that the smog laws started getting stricter. The other guys hit the mark, if it's cheap and temporary go for it, replace it later...
I've got a 307 that came out of 68 full size wagon, had 50K on it when the old lady hit a pole with it. My plan was to run it stock in a plastic 27 roadster on A rails. I would think that even stock that would be more than enough to make something that light fun.
As for the 307 vs 305? It's no contest! Have to agree there. We use several 305's in mid 80's Caprice wagons to go to shows and as delivery vehicles. With about 1000 lbs in the back plus towing a 5000 lb trailer they cruise at 60-65 and deliver 18 mpg without using the OD. With just 4-500 lbs in back and no trailer it is a steady 20-22. We have another Caprice wagon with a 350; that certainly has more power but barely gets 16 mpg even empty.
As said, a 307 is just a stroked 283. The 283 has a 3.00 inch stroke, and the 307 has the same stroke as a 327, which is 3.25. 307 has same bore as a 283. There is nothing special about a 307, but also nothing to prevent you from using it, unless you have access to a 350. Build the 350 as it is cheaper and has more cubes.
This is honestly the first GOOD press I've ever heard about the 305. I thought they were all junk. Now I'm kind of wishing I saved or gave away the one I scrapped.
Wasn't it an old hot rodder's trick to stroke your 283 with the small journal 327 crank? Why not just load her up with high-compression 283 pistons, a hot cam and some good 327 heads for an "era correct" level of performance?
The 307 wasn't a bad engine although like the cost cutting nonhardened cams they came with, the blocks were all low nickel cast iron making them more susceptible to ring wear. Many dirt trackers used to have them punched out to 4.00 and make 327s out of them. Just had to stay away from chrome or other cylider wall eating rings.They almost always came with flatops. I dont think you could put 283 pistons in one without them popping up out of the bore. Might get away withit if you used rods out of a small block 400. The 283 has a taller compression height. With a good rebuild, a mild cam and set of 305 4 barrel heads they come alive pretty decently.
Use it and tell everybody its a stroker 283! Just make sure you get a good cam and lifter set for it. Had one in a demo car car lasted 5 races...motor last 4 seasons! Had another in a '64 Impala with the old holley double pumper sittin on a Tarantula manifold, cam, headers and the little shit suprised a few people!
Hook it up to a Saginaw 4 speed and as someone else said you got double dose of Rodney Dangerfield going on !
[ QUOTE ] Hook it up to a Saginaw 4 speed and as someone else said you got double dose of Rodney Dangerfield going on ! [/ QUOTE ] That was probably me. I have a 307 /Saginaw 4-spd combo in my GMC. I bought the truck for $250 dollars when I was 13 years old. The guy threw in the engine and trans with the deal. It was what I had, so I rebuilt it and have been running it almost 20 years. It has a Comp Cams 268 High Energy cam, Torker manifold with a Carter AFB. Seems to run real well for what I need. Neal
The one I might be getting has double humps(proly 1.94/1.50), .030" flat tops, and an aftermarket cam. I didn't know you could take one to 4." with out hitting water jakets, I knew a guy that was hit water jacket after about .080"(must of been a shitty block). So why wont they rev?(they are still a short stroke motor) Is it the rod ratio that keeps it from showing decent hp or torque? -Jesse
small block this...small block that...blah blah blah. Is this all anyone recommends? LOL. Use the 307 until you can change it out to a Big Block! Especially if your planning to build a rat rod then use a RAT motor. nuff said. Satin
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