Cascade Crew

dlp

Any one know how to tell the diference between a one peice rear main 305 and 350? The guy I bought my wifes convertible from said he had a 400 SBC put in it with the stock heads. I never questioned it becuase the car made alot of bottom end tourqe than ran out of steam around 3K rpm. I put it on a lift last weekend and started poking around. The fuel pump boss did not have a cover on it and wasnt drilled out for the mechanical fuel pump pushrod. I took the transmision inspection cover off and found a one peice rear main seal. It isnt a 400.

Access to the block numbers is almost impossible with the engine in the car. I am OK with a 350, but not a 305. Any tips on indentififying what size engine is in the car would be apreciated.

Twilightoptics · Posted: Thu May 14, 2009 7:21 pm Post subject:

Only way is to get to the back of the block to see the numbers, or pull the heads and measure the bore. If it's a One Piece motor it'll say 5.0L or 5.7L on the back typically. Two piece rear motors will have just the casting number.

If it's really a 400SBC, he'd have to drill steam holes in the heads for the siamesed bores of the 400.

Xecris · Posted: Thu May 14, 2009 7:56 pm Post subject:

I don't know if it is just me, but most of the 305s I've owned and seen have had the oil dipstick on the passenger side of the block, and all of the 350s I've owned/seen have been on the driver's side. May just be the year range, though (early 80s through 91).

chevymad · Posted: Thu May 14, 2009 9:05 pm Post subject:

The dipstick is a year thing. Pre 78 motors have it on the drivers side, post on the passenger side. Unless you bought a crate motor, then you could put it on either.

If its not a crate motor, there should be some numbers stamped just in front of the passenger side head. They may tell you what it is.

dlp · Posted: Fri May 15, 2009 5:18 pm Post subject:

When you say on the back, what area specifically?

chevymad · Posted: Fri May 15, 2009 5:20 pm Post subject:

Where the bellhousing joins the block, drivers side, right behind the head.

Twilightoptics · Posted: Fri May 15, 2009 5:59 pm Post subject:

91RSVert · Posted: Fri May 15, 2009 6:18 pm Post subject:

dlp · Posted: Sat May 16, 2009 5:10 pm Post subject:

Thanks fellas. That area is really congested, plug wires, factory grounds at the back of the head, hard line for the AIR injection etc. I tried to use a mirror and flash light while the car was on a lift, could kinda see numbers but they were covered with oil and dust bunnies. Guess i need to start removing crap until I can see it from the top.