Which one of these engines would be best for a 67 SS 350 4-speed car without the original engine? Also i want to use the newer vortec heads;good bad?
(the 370 is 3.625" stroke on 4.030 bore)
Primary use for the car would be weekend driving. occasional drag race, and sometimes road trips

 

With these heads I would go with the 383.

 

1. Always build the biggest engine you can afford.

2. Torque is king, especially on the street.

 

If i could find a block with the correct date code for the car (or whatever it takes to make it #'s matching) i would build a 350 cuz that was original but if i can't i've gotta go big.

I'm shooting for lots of torque, the ability to rev pretty high(7000-7500), and still last for a long time. i hear that piston speed has something to do with longevity, which makes the 383 less appealing.

The reason i listed the 370 is b/c i have heard that 383's lose a little rev in the top end and have a share of clearance issues. Also it's bigger than a 350 giving me more torque and power. The 370 has a shorter stroke than the 383 which would keep piston speed down. It seems to me that both the 350 and 383 have their pros and cons, and a 370 is kinda a compromise between the two i guess.

What do you guys think?

 

I think that piston speed isnt going to be an issue if you buy good quality pistons and ARP waveloc pro fasteners. Buy yourself a crank for internal balancing and you shouldn't have any problems up to 6800 RPM.

If you want longetivity AND a 7500 red line, skip the first-gen block idea altogether and build yourself a fuel injected LS1 engine.

That's what I'll do if my minirammed 385 ever gives up the ghost. So far this summer it's only gone faster each and every time I've taken it out, and it used half a quart of oil in 2500 miles.

 

I think you're on point with the 370 idea. Do a google search on formula for piston speed and you'll find out a lot of interesting math. Of course with that stroke you won't have to rev the engine that high to get the performance you're looking for - that's the beauty of the longer stroke. The downside to those high rev's is finding the cam, or should I say lifters, and valve train components to keep up, then of course heads that will keep flowing and not become the bottle neck. Good luck and have fun.

 

327 is a great street engine that loves to rev.

 

Yup...you're going to spend BIG bucks to rev a street motor especially a bigger one like a 377, or 370 or 383 to 7500 rpm. Valve float becomes a big problem with even top shelf components around 7000 rpm. You really do have to go with racing equipment to get good 7000+ performance.

Mthegodfather thinks my personal favorite engine is best...that is the 327. You get the 4.0 bore of the 350, but piston velocities are kept down so you can rev them to the moon. You can make good torque and good power a 327.

I plan on building a 3rd gen starting just as soon as I find one in great shape. My plan is in about 4 or 5 years to do a 327 build up. Why? Its just about the perfect street motor. The 350 is great, but its played out. The 383 is good but you start to sacrifice mileage and logevity with that motor. The 377 (I'm not familiar with a 370) is a great compromise using the bigger bore of the 400 but the crank of the 350.

If you're looking for a good all around vehicle 327 wins, simply for originality. If you specifically want a weekend/show vehicle bigger seems to be better. In that case I'd do a 377 (or 370) and pass on the 383.

 

From your description it sounds like you want two different things, 1 - lots of torque and, 2 - high rpm. If you wants lots of torque and horsepower, build a 406. If you want high rpm horsepower, build a 377.

Regarding longevity of the first gen block at high rpm, build it right and you won't have any problems. The motor in my '69 Camaro is a '71 LT-1 block that was bored .030" in 1998. It has a stock steel crank, studs on the mains and has been routinely shifted at 7,200 to 7,500 for the last 7 years.

 

You are right about valvetrain float at 7000 RPM, but it matters not what your pistons are doing: The 327 will float its valves just as easily as the 383. The valves weigh the same.

Lets assume this discussion is shortblock related only. Power is a function of RPM and effective volumetric efficiency. Build a relatively wide bore, like the 4.125 inch bore to aid airflow entry and exit. If you are worried about longetivity, reduce the stroke. like Steve said, go 377.

However my personal opinion (and I think Steve's from the sound of it) is that the 3.75 inch stroke will be fine for your high RPM street motor if you pick the right components. The percentage of time you spend at the high RPM level on the street probably wont be very much anyway: You'll either behave and drive around at lower RPMS most of the time, or else you wont, and then the local police department in conjunction with your state's DMV and your insurance company will dictate when you get to drive the car.

 

I'm gonna side with Steve and say build the 400 or 377. He hit the nail on the head.

A nice mild 400 will make a great cruiser, plenty of low-end torque.

- Justin

 

Correct, I didn't mean to infer piston speed equated to valve float it doesnt. But you get more logetvity out of a motor keeping piston velocity down. That was my only point, sorry if it was confusing.

 

I have to go with the 327 ive built 2 of them the last 1 I still have in my second gen.I have about 2000.00 bucks into it and it bets the car down the track in low 13s and even a few high 12s and every time I pull into a cruise
night or car show befor I even open the hood Ive been asked if its a BB
ITS A 10:1 compression 76cc heads with the small valves 194 and 150
an ex284 cam 240/246 duration with a 510 lift on stock springs
a set of badger .240 dome tops and a 600 cfm edellbrock carb and eps intake
100 shot of nos 3500 stall stage 2 shift kit 342 gears and 7 year old 295 50 15 stree tires
the combo work perfectly for me
cheap to build and reliable

 

I'm a huge 327 fan. What did you build the bottom end with? What bearings rods etc? What are you revving too? How many miles are on the motor?

 

ONLY HAS ABOUT 10,000 KM ON IT
stk rods
stk fasteners
cast pistons
clevite bearings
6500 rpm is about as high as ive had it but the last one i built
i stopped at about 7400