Hi all,
With the swap meet coming up, I'm going to keep my eyes peeled for a motor/tranny/TPI combo. Is there any easy ways to spot a 350, -vs- a 305??

Thanks,

Cam

 

Check casting numbers, or measure the bore.

Those are the only ways to be sure.

 

Look on the top of the block, on the drivers side, near the back and above where the tranny gets bolted on. Late model 305s have "5.0LG" cast in the pad, while the 350s have "5.7LG" in the same place. That's the easy way. Also, I believe the 350 blocks will have a "638" stamped on the outside. At least, the one I'm building does. That came from an '89 GTA.

 

638 is the last three digits of the casting number. That will be different on all blocks. The only way to be postive is to measure the bore or check the casting numbers.

 

Here's a pic of what you're looking for at least on most 86 and up blocks. You can see it with the engine installed in the car, but you'll have to wipe a fair amount of grease and other crap from back there. If the seller is lying, he probably won't let you look at the displacement code or casting number. Also the 8th digit of the VIN on 350 TPI cars is an "8" where as 305 TPI's are "F".

 

There is a 638 on the front/bottom of the engine, all by itself. There is also a 627 on the passenger bottom side of the block, I believe around the knock sensor area. Now they mean absolutely nothing in terms if either number stating what size the motor is. I have a 305 and when some jackass said that 638 definately means 350 and no other person discredited this info, I naiively bought 350 heads, injectors, and computer. All in vain.

Like it was stated above, either remove the head and measure the bore, or somehow clean the back "shoulder" of the block below the windshield wiper motors and see what it says.

 

Print the Mortec list and have it with you. They do a pretty clear job showing where to look etc. as well.

MorTec, Inc. Home Page

hth.