Questions about '71 engine and trans.

[Myself]

I found a '71 Longhorn that the guy says is in good condition. It has a big block and auto trans. Is this most likely a 402 and TH400? Will it be a 4 bolt main? I believe the truck has ps, pb, and a/c also.

[71chevylowrider]

all you need to do is talk to LongHorn man, he knows Longhorns like you wouldn't beleive.

[71chevylowrider]

Here's his website for instance

http://www.longhorntrucks.freeservers.com/

[kevenj]

Originally Posted by Myself

I found a '71 Longhorn that the guy says is in good condition. It has a big block and auto trans. Is this most likely a 402 and TH400? Will it be a 4 bolt main? I believe the truck has ps, pb, and a/c also.

If it's the original engine/trans combo it should be a 402 (marketed as a "400") and TH400. Easiest way to tell on the trans is a TH400 uses and electric kickdown while the TH350 has a kickdown cable. Also the pans are different - - hard to describe the 400 pan but it's an "irregular" shape while the TH350 pan is basically square with one corner cut off.

I do not believe the 402's in trucks were 4 bolt main but I could be wrong. I have a 4 bolt main 454 in my boat and there is a large pipe plug in the block just above the oil filter. I have been TOLD that all 4 bolt main big blocks have this plug and 2 bolt mains do not. I have nothing to back that up, just what a guy told me that usually is not full of B.S. so I believed him :-)