Whats up. This is kind of weird but I did notice that we are both the same age and we both have Chevelles and we both live in the same city. What school do you go to. Anyways, get rid of the 307. If you want power for cheap go for the 350. If you want to drag race the Chevelle then you dont really have to worry about topping out. Topping out is sort of a jap car thing. What matters is how quickly you can get down that quarter mile.

 

If top speed is 45 mph, there's something--or several somethings-- very, very wrong.

Start with the basic tune-up kind of stuff. You'll want to know the fuel pressure; initial, centrifugal, and vacuum timing; do all of the cylinders recieve strong spark; do they have compression; do they run; is the air filter plugged, choke stuck closed; vacuum leaks; carb linkage will allow full throttle, and the secondaries (if it's a four-barrel) open; etc.

Once the engine is sorted out, you'd look for a restricted exhaust. Used to be pretty common. The exhaust pipe is double-wall, and the inner wall collapses and blocks flow. You cannot see the problem because the outer wall looks fine. Could also be a bad torque converter sprag. Do the brakes drag?

 

CheZeppelin. I goto Shadow Mountain High School. How bout you?
Ya I figured there was some other problem. However engine is the only thing we dont know how to fix. So my best bet is taking it to a shop and seeing whats all going wrong. The problem with getting the 350 is price. Called up a few shops and it will run me about $2500 for the crate and assc. Ill prob take it here to the shop this week and have them run some tests to see whats going wrong.

 

I go to Washington High around the 19th ave and glendale area. Your best bet is not buying a brand new crate engine because of the price but find someone who is getting rid of their 350 or finding one in a junkyard. However these engines may not be in the best of shape and will more than likely need some work done, but it will be a lot less cheaper than buying a crate motor and you get to build this engine yourself and learn a little. If you have any more questions you can email me at Chezeppelincorps@cox.net ive been there and done that and I can more than likely help you with a few things, I also know a few good shops around town that can give you good deals too.

 

Guys, that little 307 may not be the quickest thing on the block, but my wife's 70 Chevelle had one in it from the time she bought it in 1970 until the car was rear ended in 1985, and it ran pretty good! Do what the guys here recommend. Do a compression check of ALL the cylinders and if the numbers are close, do a GOOD tune-up...plugs, points, timing, etc. That car should have NO problem doing 60, 70, or MORE...alot more (at the strip, of course.). It's a good dependable little engine and by putting a few bucks into it, you can save for a decent 350 and still have a good runner in the meantime.

 

Malibu is correct. Its down to whether you want a good solid little engine that is realiable or a 350 with a little more power. Power is good but in for a broke highschool kid reliability and cheapness is better. Trust me its no fun having your badass Chevelle breakdown with your best girlfriend in the car.

 

My August, 2004 copy of CHP has an ad in it from Competition Products for an "Esky Short Block 350, no core for $574.95!!

And Midwest Motorsports also sells unassembled 350 claimer motor short block kits for like $700+ so maybe the freight wouldn't eat you alive compared to a $2500 quote price for a crate motor??

I would buy a Northern Automotive Parts 307 motor overhaul kit and rebuild it myself before I would buy a crate motor for $2500.

Or maybe you can get a comparable 307 kit from Powerhouse, (enginekits.com)??

I guess what I am poorly mumbling about is, look around in the mag's and see if you can't come up with either a 350 short block worth the money or an inexpensive 307 rebuild kit... B/c I know how tight bucks can be at times..

Claimer motor kits MAY not be the best in the world BUT for the money they are generally good value imho!!!

pdq67

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Start with the basic tune up things such as the points and condensor and the dwell setting using a meter, looking at or replacing the spark plugs and dist cap, rotor and plug wires. They don't need to be expensive parts, the good old standard replacement parts at Napa will be fine. Check this stuff out and post back here and let us know.

 

yeah I would do a major tune up and check everything out. those 307's are running machines, you just cant kill em.......lol. I had a 307 in my 1st chevelle that ran like squalded dog. I also had another in my chevelee that I have now and still have it. Im going to a 454. also Ive seen 307's in the stockers at the drag strip run better then some 350's. I guess its all in what ya want but before I spent 2500.00 id stick 250.00 into that 307. it could be something minor, A rebuild kit shouldnt cost that. alumn. intake and 4 barrell carb youd be good to go. I wish ya luck

 

Most of the 307's had low nickel blocks that don't wear as well as the ususally better 350 blocks. (look for a 5 or a 10 or higher number cast into the block behind the timing chain cover, that indicates the nickle in the block) This is why most people think they're junk.

The 307 isn't a bad motor. Mine will roast the tire for about 200 feet with a 2.73 open rear. It'll also get upto well over 75 on the highway. Get it checked out, I'm sure you'll find something stupid like overly retarted timing or a faling fuel pump.

You can get headers and duals, a 4 barrel and aluminum manifold, hi-pro ignition, then when you find a 350 you can swap all that stuff on.

I'm finishing a full body off resto on my 70 and I'm running out of money, so it looks like it will still be running the 307 for a little while longer which is ok with me...

If your motor has good compression and oil pressure here's what I'd to (actually it's what I am doing).

Edelbrock performer manifold (swapmeet - $75)
Holley 600 cfm vac secondary (friend - $100)
Headers (Summit - $100)
Dual 2 1/4 exaust with turbo mufflers, (Local shop - $300)
Summit 262 cam and lifters ($79.95 PN: Sum K1102)
Edelbrock valve springs (Summit $42).

You'll also want / need a timing chain, gasket set, good ignition tune up, and if the TH350's any good I'd swap that in place. You'll have about 240 - 250 HP and a real good running engine. Probably high 14's, low 15's at the track.


David

 

Thanks for all the advice guys. I believe ima just fix this little 307 abit, after i can get it running again believe my starter just went out today goto work with it abit more tomarrow.
Ill take it to the shop and get it checked out once its on the road. Then most likely pick up a block at a local junkyard and just put parts on as i get the money Unless i can find a pretty good deal on a good running motor. Ill keep yall up to date on what other information I find out

 

I've been driving a 307 car for the better part of 14 years... if you aren't ready to take the plunge into a new motor yet, just give it a tune up and go through all the obvious stuff as everyone else mentioned. Unless it has some serious internal damage, it probably just needs a tune up.