Puttin' Perfume on a Pig...307 Tech?!

Must have been a Quaker motor....

 

I’d rather have a 307 over a 305 any day. I had a slightly O/T Chevy C-20 with a SM-465 and a 307, factory 4.57 gears, the engine was tired, but ran great, that old truck was my first tow vehicle when I started bracket racing. It used so much oil that I put drain oil from my school buses in it (I started as a bus mechanic). Everyone at the track was a bullshit artist when you asked about their engines, and I started telling them mine was a “307 truck engine with a cam”, it ran 11.90-12.00 at the time. I’ve read the 307 had cam trouble, did it use a different cam than a low HP 327 or 350? If not, then why do people pick on the 307 for cam troubles?

 

No idea what the neighbor I bought the Chevelle used to only keep topping off the oil level.

 

Its still going all going to depend on trashing the stock heads , which ones you’re going to use and rear gears choices and your target 65/70 rpm range. If you mentioned it somewhere I did not catch that.
If you want to get nitty gritty the rear tire Diameter matters too.

305 HO head and this 262 cam with th350, old school P9 Vega converter 308 gear worked extremely well. If I would have had a 700 trans I’d choose a 3.42 min rear gear

 

It will have 305 HO 416 casting heads.

Not having the loose converter is what has me concerned. I have never had a lock up converter in a hot rod, much less a smaller cubic inch motor with a lock up.

Our late model pickup goes into OD at 45 mph which is about 1,500 rpm. How bad will it be with a cammed 307 if the trans shifts into OD at 1,500 rpm? If the cam specs say 1,500-5,500 rpm, am I good? Or will it struggle?

 

If you think about it a 307 is a 283 stroker motor that a couple of high school kids could have put together on a nickle and dime budget in the 60's from parts scrounded from a junk yards core pile. The gent who owned the first shop I ever worked in in Waco TX, J.T. Carpenter made regular trips to M Lipsitz in East Waco to pick through the engine pile to see what he could scrounge for blocks, heads and cranks for his circle track cars. It wouldn't have been hard to dig a good 283 block and 327 Crank out of that pile with a set of good rods and a decent pair of heads. A lot of hot rod engines came out of that pile by the pound.

Back in about 1986 I did a horse trade for a 70 C-10 for my son. Truck had a 250 in it that was pretty tired and he was spending about as much for oil as he did for gas on it . I had a 307 that had come out of a Chevelle that I had put together for my wife with a 350 that I had had in about four different rigs.

We did a ring, rods and mains redo on the 307 and I found a Z28 take out cam with the lifers all numbered in and egg carton at the Portland Swap meet for 25 bucks and put a new timing chain in it. I dug out a pair of 283 power pack heads and ground the valves and stuck them on with the Performer intake that had come on a 75 1 ton I had had for a while. Spread bore Holley 4 barrel that I picked up somewhere and we stuck it in the C-10. That truck was a bit of a sleeper and he messed with a few mins in short street races. It also pulled 16 mpg on a road trip to Texas and back.

 

I wouldn’t have 1500 rpm as the target - not with a carburetor and OD.
I wouldn’t look to your late model pick up for guidance either , because there’s no electronics.
If you want it to go down the road like you’re late model pick up then you need to go a different way that includes a whole bunch of late model stuff.

You can get a loose converter for your 700 trans, that will increase low end for fun and spirited driving especially with that low first gear. Choose your rear gear against your OD gear to lock up at 2000 rpm 65 mph. The stock 1-2 shift recovery sucks though. I think the 200 is better option but it needs money to work better.
The trade off, a th350 and rear geared to hit the 65rpm around 2000. Nice Highway manners and fun enough stop light adventures, provided the power is there.
Millions of autos, billions of road miles this way. Millions of races won.

The introduction of the OD trans by GM was necessary because engines were castrated and anemic at best, so they needed mechanical advantage to overcome low power and economic regulations.
the low first gears to get them moving and the OD to boost economy. Us hot Rodders can use the OD but not both sides of it. You pick extra low end grunt and acceptable Highway or exceptional long distance and enough low grunt to get you out of your own way. Not sure if you can get both.

Running an engine below the power band is actually worse of everything

 

I wasn't aiming for a 1,500 rpm cruise rpm on the highway. The modern truck doesn't live there either. I was wondering what would happen if the trans did shift into high gear at 1500. Would the engine have the low end grunt to accelerate from there or would it just bog down until it downshifted? How small of a cam would I have to go to not have a problem? How big can I go and it be tolerable. I have no experience with a combination anywhere close to this.

 

How heavy is the car?

 

3,000 lbs?

 

It'll probably pull it, but it's not going to break any acceleration records. You know you can defeat the lock up so it doesn't engage at all, or you can set it up to engage it with a manual switch. I haven't done it myself, so I can tell you how, but I know guys do it. Do an internet search.

 

estimated curb weight?
Reality based driving goals?


The combo is capable to give you something near 300 hp. Maybe 285 maybe 325.,,,, so don’t expect to be a drag strip Godzilla, or serious contender in street races.
On some extensive desk dyno work, The cam I mentioned made the most Average HP thru the rpm range. That’s AKA under the curve. The torque curve is very flat too. That’s where your street driven car spends the majority of its time. Bigger cams made more peak power but less average power. Complete as done in the car and real world driving it’s was really freaking nice! Forget that’s cast off parts and perfume pig ,,,, fun ride.

That trans needs it tuned to downshift when it needs too other wise it’s going to RATTLE, the trans needs tuned to 3-4 shift and lock when needed. I can’t tell you how yours will do but I had no problems with my set up in a 4000 lb vehicle