'87 TBI 350 in Blazer

[pitbulls'n'blazers]

Hi I have a couple of questions about the stock 350 that's in my '87 Blazer. First is it a 2 or 4 bolt main engine? Also what is the cfm on the stock TBI?

thanks!

 

[4X4HIGH]

The block could be either a 2 or 4 bolt main. IIRC the factory TBI unit only flows 470 cfm

 

[pitbulls'n'blazers]

Is there a way of telling if it's 2 or 4 bolt with out taking off the oil pan?

 

[4X4HIGH]

Nope, must pull the pan to find out.

 

[pitbulls'n'blazers]

I'll check it out when I change the oil. Thanks for your help!

 

[4xcrazy]

uuuh, yeah, run the casting numbers on the rear driverside tab of the block,,,,,

 

[JEBSR]

Only sometimes. allot of casting numbers are either/or.

 

[sandawgk5]

Look at the vin number. To my knowledge in 87 the K5s only came with 2 bolt mains. The HD emissions engines could be either or but not the K5 engine.

Ira

 

[dyeager535]

If you get the chance and remember, when you find out, post the suffix code and whether two or four bolt in this thread. I'm trying (not very hard) to see if suffix codes can be used to determine two or four bolt. Pointless I know, but so far it holds true. If an engine with suffix code XYZ is a 4 bolt, so far any other engine that is the same suffix code is also.

Suffix code located on the flat pad of the block behind the alternator, just forward of where the head meets the block.