This is what I was to believe was in a 1988 Iroc 350. In this year the block was using the 1 piece rear main seal design, and also was using a roller type setup, including cam and lifters.

Now, I am looking to buy this motor that was supposed to have come from a 88 Iroc, and has a recent rebuild on it. The number stamped on the block is #14093638 which is a 1987-1995 2 or 4 bolt main, roller or flat tappet, one piece seal. Was this casting put into 3rd gens in 1988? Why are some roller and some are not? Which cars/trucks got which?

The motor I am looking at has a flat tappet cam in it. I have a aftermarket roller cam and also roller lifters. Will my parts work with this motor? Is any machine work involved? What would a conversion like this cost if it is even possible?

Thanks

 

Try the history board, I bet somebody on there knows the answer

 

Does this block have provisions for a spider in the lifter valley or a cam retainer on the front of the block? If not then this isnt right. Also, are you sure this motor has a 1 piece rear seal in it? In '86 they swapped to a 1 piece rear seal, but still had a flat tappet cam, some late 86 blocks had the bosses in the lifter valley for the spider. In 87 as far as I am aware all motors got a roller cam and centerbolt heads. If this motor has a flat tappet cam in it then it is either not an 88 or has had one put in it by somebody. You can tell by looking for the bosses for the spider running on top of the cam in between the lifter bores there should be 3 bosses there tapped and the tops of the lifter bores should be machined for the retainers. If those things are not there then this is definately not an 88 engine.Also there should be a little machining done to the front of the engine behind the cam sprocket for a cam retainer with 2 bolt holes for it. I hope this info helps.

 

I have exactly that block in another car, it came out of an 88 iroc. Its a one piece rear main, 2 bolt, and has the provisions mentioned above for the roller cam.

Its possible to put a flat tappet cam in a roller block so maybe someone did that. Look for the stuff for the roller cam to be sure.

 

It could also be out of a fullsize van or truck. I purchased a 350 from an '87 van to build and put into my '86 Z28 because it has the one piece rear main and a flat tappet cam, like my original engine. Trucks and vans didn't get the roller cams until '88. Maybe this 350 was a leftover '87 installed into an early '88 body?

 

I will have the guy check for the things you guys mentioned above. If the block is indeed equipped with the spider tray and cam retainer then will my roller stuff go right in with no problems? What if it doesn't have those provisions, is my stuff not going to work?

 

Well you say you have an aftermarket roller cam and lifters... is that a stock factory replacement deal or are they for cars that did not originally have roller lifters?

The setup for cars not originally equipped with rollers will work on both, the factory setup will only work on the block with the provisions.

 

My cam and lifters is made to work in the factory roller setup. Assuming that this block doesn't have the provisions made, what would an approximate cost be to make it work with my cam and lifters, if that is even possible? Depending on the answer to the first question, would it just be easier to locate a factory roller block with the 1 piece seal rather than trying to convert the non roller block over?

 

If you have the provisions for the spider and the bolt holes are drilled and tapped for it, then you will need to get the link bars and spider for the factory type roller lifters. I belive these cams are retained from forward thrust by a bolt on plate that fits in a groove in the front of the cam so you will need to get the plate also (If it truly is a roller block fitted with a flat cam)

If its a flat cam block you will need more expensive (approx 300-400 bux) retrofit hyd. rollers, a means to keep forward thrust limited since there's no provision for the factory retaining plate (thrust button needed)

Either way you will need shorter pushrods.

It may be better to skip this block anyway unless he still has all the roller parts that were removed: pushrods, spider, link bars, front retainer plate and all the hardware as this stuff will add up unless you get them out of the j-yard.

 

Thanks guys,

Thats what I needed to know. Just trying to make my life as easy as possible with this motor swap. I appreciate all the help.

 

They put roller cams in Passenger Car motors in 87-up, but not for some of the trucks. The trucks were more than likely flat-tappet. I've rebuilt a 91 305 for a truck and it was factory flat-tappet. I've rebuilt my 305 L03, and it's roller cam.

The passenger car LG4, L03, L05, LB9, L98 and others got roller cams in 87. They also have 2 bolt mains.

The trucks, LG4, L03, L05 got the flat-tappet treatment in 87-up, but not sure when they started putting roller cams in them. The 350 is the only motor I think came with 4-bolt mains.

I've gathered this info, so if any of you guys would like to dwell on this, I will be interested to know others input.

-ws6formula-

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1989 Pontiac Formula WS6
69,000 miles.
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305 TBI, 4.10 gears, SLP Zexel/Torsen Limited Slip Differential, 700r4 Corvette Servo, LT4 Hot Cam/Valvesprings, GM Aluminum Driveshaft, 2700 RPM Stall, Edelbrock Performer RPM intake manifold, Turbocity TB. Ran on 6-19-2001 again: UPDATED: 14.1 @ 97.68 mph. Dyno'd Bone Stock @ 172.6 rwhp, 266 ft-lbs. of rw-torque.