How can I tell if my motor is really a 350 or a 305?

speedindevil · 05-24-2005, 07:06 PM

Hey guys, I'm fairly confident with all your infinite knowledge that one of you guys can tell me where to find the casting numbers on the block of if there is some other way to tell, It's an 88 1500 4 wheel drive. For some reason I have doubts about it, just doesn't seem to have the power I think it should, My buddy's 5.3 pulls harder than my truck seems to. Thanks fellas

goinbig · 05-24-2005, 07:13 PM

On all Chevy V8's the engine codes are stamped in the block on a pad...directly forward of the right hand cylinder head.

Also, Many 305's have "305" or "5.0" cast into the block area that bolts to the transmission...more or less behind the distributor...but not directly behind (not sure all 305's have this though).

Besides that, take off the oil pan and measure the bore. Or take a P&G meter and measure one cylinder, then multiply by the number of cylinders you have and there is your displacement.

2000CAYukon · 05-24-2005, 07:35 PM

This might help for casting number location: http://www.mortec.com/location.htm

//2000CAYukon

mbumgua · 05-25-2005, 09:33 AM

Go to carfax.com and input your vin number in the free check area. If the engine hasn't been changed it will give you the displacement of the engine. The 5.3 has almost 100 more horsepower than your 88 350(190 hp)

goinbig · 05-26-2005, 11:31 AM

Only problem is there's no certain way to know if the engine's been swapped out...with out know what engine is in there!

J-Ri · 05-27-2005, 03:50 AM

If you still have the owners manual, it will tell you what each VIN character means (or I'm sure someone else has one for an 88. The 8th digit is the engine code.

For my 86, "M" and "L" are both a 350. "M" is a 4 bolt main, and "L" is the standard 2 bolt. They probably changed the engine code when they went to TBI, however, so this may not help you any.

Vittro · 05-29-2005, 10:54 PM

if ya know the engine litre then ya know the size i have a 4.3L so its a V6 "262", a 5.0L is a V8 "305" and so on 5.7L V8 "350"

lonelywolf8588 · 05-29-2005, 10:58 PM

Your buddies 5.3l hauls compared to the 5.7l because of programming on the computer and gearing.

big_blue_chevy2006 · 05-30-2005, 11:20 AM

look on the fan shroud and there should be stickers there like i think its on the belt routing sticker or the other one im not sure but it should say the litre size and then you will know.

LT1 Kayker · 05-31-2005, 01:06 PM

look in your dash board or cubbyhole whatever you call it. There should be a big dirty sticker with a lot of numbers on it, thats your RPO codes. Look for L03, thats a 305 like I have. I don't remember what a 350 RPO code is but if you see a L03 like at the top right of the sticker thats a 305 5.0.

mbumgua · 05-31-2005, 01:39 PM

Speedindevil wants to know how to tell what the motor is if it has been replaced with a 305 or a 350.

jveik · 05-31-2005, 09:34 PM

Quote:

Originally Posted by lonelywolf8588

Your buddies 5.3l hauls compared to the 5.7l because of programming on the computer and gearing.

actually, the newer models with the 5.3 liter, like a 2003 truck, (im assuming its about 327 cubic inches) make more power than a late eighties and early nineties 350 did. i think its just the design. engine design has come a long way even over a period of only 10'ish years. my dads 1990 silverado 350 (5.7) only made about 190 horsepower and i have heard the newer 5.3 can make more than 270 horses or somewhere in that range.

it is true tho i bet the rear ends are different. if the transmissions are the same and you both have a speedo, then get both trucks in overdrive and locked up torque converters (assuming you both have the same automatic tranny), anyways, once youre both locked up, both of you go the same speed, lets say 60 mph, then both of you see what rpms youre spinning. if they are different, then the one that is running at a higher rpm has better gearing in the way of power and will appear to be more powerful even with the same engine

POST REPLY TO THIS THREAD