[No4njunk]

I'm looking for a 350 block for 383 build. Needs to be 1 piece seal. I know they became available after 86. Just want to be certain when looking. I also want the mech fuel pump. What would I look for on the block to be certain? I know there are some very knowlegable people on this site.
Thanks,
Scott

 

[Fred Ficarra]

Mechanical fuel pump on an 87 block? My truck didn't have one. But I'm not the expert.

 

[novaderrik]

Mechanical fuel pump on an 87 block? My truck didn't have one. But I'm not the expert.

most of the blocks are still machined for the fuel pump and came with a blockoff plate on the TBI and Vortec applications, but there are some blocks that have the mounting boss cast but not machined.
as for what to look for- look for the one piece rear main seal retainer- it is an aluminum piece that holds the rear seal and bolts to the block around the back of the crank. the older two piece seal blocks don't have this piece.
also look in the valley under the intake manifold to see if it is setup for a factory roller cam. there will be 4 (i think) stands cast into the center of the valley that are tapped down from the top to bolt down the "spider" that holds the lifter retainers down. also the tops of thel ifter bores are machined down flat so the lifter retainers can sit down flat.
under the timing cover, the area around the front of the cam will be machined flat with 2 bolt holes tapped for the camshaft retianer on the roller cam blocks. the non roller blocks won't have this area machined.
some truck blocks and 86 passenger car blocks with the one piece rear seal don't have the provisions for the roller cam, and others have the stands cast in but not machined. the only sure fire way to tell a one piece rear main roller block from a non roller block is to actually look- you can pop off a valve cover and shine a flashlight down the pushrod or oil drain holes and see if it has the roller cam provisions. the best places to look are in 87 and newer passenger cars or 96-99 trucks and vans with the vortec motors. those all had roller cams and one piece rear seal blocks.
also- make sure it is a 350 and not a 305 by looking at the top surface of the bellhousing. a 305 will say "5.0 liter" and a 350 will say "5.7 liter" in raised cast letters. and you want to make sure you aren't looking at an LT1 block- when they are stripped down to a short block, they look a lot like a regular small block, but the front of the block looks completely different due to the different water pump setup on those compared to a regular small block.

 

[BillK]

Scott,
One thing you need to be careful of if you plan on using the factory style hydraulic roller lifters. Some of the early 1 pc seal blocks used in trucks "appear" to be machined for the roller lifters but ..... they have a "relief" in the top 1/4" or so of the lifter bore that will bleed off oil pressure if used with the factory style roller lifters I found out the hard way when I used one of those blocks for an engine I built for my 85 Blazer I have attached a picture of the lifter bores to avoid.

 

[67CamaroRS/SS]

Scott,
One thing you need to be careful of if you plan on using the factory style hydraulic roller lifters. Some of the early 1 pc seal blocks used in trucks "appear" to be machined for the roller lifters but ..... they have a "relief" in the top 1/4" or so of the lifter bore that will bleed off oil pressure if used with the factory style roller lifters I found out the hard way when I used one of those blocks for an engine I built for my 85 Blazer I have attached a picture of the lifter bores to avoid.

Bill, I am a little confused here. Are you saying that these blocks "look like" a factory roller block, are in fact a tappet block?

 

[ace's68]

I bet you could tap that and put in a screw or plug.
A lot of the 010 blocks from the late 80's are still flat tappet style, but one piece seals which is a plus. The 010 that I picked up for free was from an 87' truck, flat tappet, not machined for spider tray, and the fuel pump was not cut.
It's prob going to be some what difficult to find a roller with the fuel pump boss machined.

 

[77wolf10.85]

If you look at complete engines look for a plastic timing cover(that'll get you into the vortec era) and a round flexplate flange, and the flexplate will have a small counterweight. And behind the flezplate the aluminum 1 pc seal housing will be visible but what will catch your eye first is the studs sticking out that hold the seal adapter on.

Looking at bare blocks there's lots of dead give aways. From the front look for the 2 threaded boltholes for the cam thrust washer. At the rear you will see holes/dowel around the rear main for the seal adapter. And above the rear main the 3 oil galleries are on a common boss that is machined flat, unlike the older blocks. From above the bottom of the crankcase back by the rear main on the pan rail there is a bolthole missing on both sides compared to the older blocks(where the 5/16 screws go). Both pan rails are straight as an arrow compared to the old ones but the oil filter side still has a little dogleg.
From the vee,,,,,Ray Charles could spot the 3 threaded bosses in the main oil gallery to secure the spider for the rollers.

Here's some pics I just shot of mine for ya. I bought it outright from my bud who owns a machine shop. It's a .040 over and clearanced for 3.75. I screwed around and let it get wet while I was overhauling my shop, so I get to spend an extra day cleaning this one when I get around to building it. I clean the damthings 1 to 2 days anyway. Sorry I forgot to take a pic of the fuel pump mount, but it is bored for the rod.

Here ya go

 

[prostreet69camaro]

If you do use a block like this for a hydralic cam you need to put bolts in the lifter valley where the 3 bosses are. If you leave them out it will not have any oil pressure because oil will squirt thru the holes.

Ask me how I know???

 

[BillK]

Bill, I am a little confused here. Are you saying that these blocks "look like" a factory roller block, are in fact a tappet block?

Charlie,

That is correct. If you look closely at the lifter bores in the picture I posted, you will see that the top 1/4" or so of the lifter bore is larger that the rest of the bore. If you put a factory style hydraulic roller lifter in one of these blocks, the oil hole in the lifter will come up into that "counterbored" area at full lift and will bleed off oil pressure. The "real" roller blocks are identical except that the lifter bore is the same size all the way to the top.

The blocks are identical in all other respects.

 

[bill3337]

I have a bare block from an '87 Iroc 5.7 liter, that has had the block ground smooth and painted, and is machined for a 383 crank. It had factory roller lifters and is machined for the mechanical fuel pump. It has been bored .040 over. I can take pictures if there is something in particular you'd like to see. I bought another brand new GM 383 bare block from Sallee Chevrolet for under a $1000, so that might be the way to go.....it comes all machined for the stroker crank........Bill