i could use some help, i own an 88 chevy 5.7 4x4 p/u. at 264,000 the engine is tired.

i have a rebuilt 85 5.7 that was just rebuilt i also have a fresh set of 88 5.7 cylinder heads, that im going to install on the 85 block so i can use the original intake and fuel injection set up. so here is the questions

the 88 is an origainl roller type cam/lifter set up, one peice rear main seal, dipstick on the passenger side,if i remember the 88 block has a different lifter valley  set up than the 85 so what to do ??

i know i need a different flex plate, im not sure if there is a provision on the 85 block for the knock sensor, if you can give me some advice or let me know if i forgot something,

 The engine blocks are primarily the same.  There should be a pipe plug in the side of the block on the older style motor right where it's needed.  Also if you didn't want to go through the trouble of changing the heads over you can oval the center 2 bolts in the newer style intake  to the correct angle for the older style heads and intake gaskets.  The fuelly heads from 87 to 92 were extremely bad flow wise.   Most had a spiral casting inside the intake chambers for better fuel atomization but really all it did was decrease horsepower. Also most engines came with the smaller 1.86 or 1.94 intake valves.  If your 88 has a good set of heads I'd stick with those.   I swapped out a 305 TBI from an 89 Firebird formula to a 350, block was a 79 4bolt main. The lifter valley in your 85 block won't have holes drilled for the lifter girdle.  But the flat tappet cam and lifters will work just fine with your computer that year since the primary signal comes from the distributor not a cam position sensor located elsewhere like the newer style engines.  Your distributor still controls your timing for the most part and the cam gear didn't change so you should be all set to go.  Just remember when you time it to unplug the timing advance and set it to the recommended advance/retard. 

Brandon

Brandon's Auto

Brandon,

I have a 1993 K1500 with a 5.7L TBI.  I just recently removed the heads with the plan to do some minor porting.  They to have the same spiral ramp casting in the intake ports.  Are they worth my efforts to port or am I just wasting my time.

Mike

If I remember correctly those heads still have the small runners and pretty low flow numbers.  You'll gain a little bit but probably not very much.

I would say go for porting as it is always needed though you will gain a little as mentioned in the above post.

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