[Volla SA]

I am looking to buy a 307 V8 engine. How do I know it is, in fact, a 307 V8 just by looking at it? I don't want to buy from someone claiming to have one, only to get it home and it doesn't fit in my car because it is a 305! Any tips would be appreciated thanks!

[DoubleVision]

You look up the casting numbers. Since you mentioned a 305 as well. all small block chevy`s - 262 - 265 - 267 - 283 - 302 - 305 - 307 - 327 - 350 - 400 are all the same externally, all the bellhousing patterns are identical, the external dimensions are identical. This is why small block chevy`s interchange with so many different pieces from different size small block chevy engines so even if the engine in question is a 305 it will still bolt up and work just fine. The only difference is internally, difference engines had different bore and strokes and different cranks, but that makes no difference on a external scale where what bolts up counts. The casting numbers on the drivers side bellhousing flange of the block, once you have them you can look them up
here:
http://www.odellam.com/
The first set of numbers are cylinder heads, scroll down to block casting numbers.

[joe_padavano]

Originally Posted by Volla SA

I am looking to buy a 307 V8 engine. How do I know it is, in fact, a 307 V8 just by looking at it? I don't want to buy from someone claiming to have one, only to get it home and it doesn't fit in my car because it is a 305! Any tips would be appreciated thanks!

A 307 CHEVY or a 307 OLDS? These motors are completely different and do not interchange. The easy way to tell an Olds is the 5-bolt valve covers (4-bolt on the Chevy) and the oil fill tube that goes into the block right above the water pump. Also, on an Olds motor there are casting numbers on the ledge next to the oil fill tube that will tell you what motor it is.

[Volla SA]

Hi, thanks so much for the info. It is a 307 chev that I am looking for.

[Greg T]

If you're not looking for a date/period correct power plant, why not plug in a 350?

[eloc431962]

What kind of ride are you working on anyway ? Body style / year.
What are you putting the engine in.

Cole

[Volla SA]

I'm working on restoring a 1969 Chev Constantia/Holden Brougham (2 speed automatic "powerglide" transmission) here in South Africa. Apparently, in Australia this exact car came out with a 307 so I should be able to pull my straight 6 and put a 307 in without any mods.

[oldbogie]

Originally Posted by Volla SA

I am looking to buy a 307 V8 engine. How do I know it is, in fact, a 307 V8 just by looking at it? I don't want to buy from someone claiming to have one, only to get it home and it doesn't fit in my car because it is a 305! Any tips would be appreciated thanks!

Actually if you picked up a pre 1986 305, it would drop right in and you wouldn't know the difference till you took it apart. On the outside anything that connects to or is fastened to the 307 will also go right onto the 305 and the 305 will go into any vehicle that had a 307. Same would go for 283, 327, 350 and some 265s.

Stating in 86 you start see changes, the angle of the center 4 (2 per side) intake to head bolt angle changes from 90 to 72 degrees measured from the head's port face, so this drives a matching intake or modification of the bolt hole angle in the manifold. A change from carbs to injection, Throttle Body Injection (TBI) for trucks and some car models and Tuned Port Injection (TPI) on some car models. Rear crank seal changes from the older 2 piece to a 1 piece, this is is easily accommodated across the change line with the flywheel or flexplate that fits the crankshaft used, everything else still bolts up. The rocker covers morph from the older perimeter bolts to center bolts so the head and rocker cover need to match. For the most part trucks stayed with flat tappet cams, though the block might be provisioned for a roller. Most 305's in cars went to the factory roller cam, from the outside you can't tell. Engines that had TBI or TPI injection use a version of the HEI distributor where the advance is computer generated, these can be changed back to the earlier distributors if you're not using injection and the computer, this is a drop in swap.

So a 305 really wouldn't be an unpleasant surprise nor would a 350, the pre 1986 is a bolt in, the post 86 takes some minor tweaking for the flywheel/flexplate, distributor, and messing around to be sure the heads have the correct rocker cover and intake will bolt up, no big deal. The new versions leak a lot less oil from the crank and rocker covers.

Bogie

[Volla SA]

Thanks Bogie, this input helps me a lot!