Finally got to pull my engine out and start cleaning it up. Its a '89 IROC 305/T5 car but PO said it had an '86 engine in it. I've pretty much confirmed its a non-roller block with this picture...





Here's the numbers off the back of the block.








So here's a question,
Front serpentine setup





I started taking front accessories off and found I'm missing a bolt hole. My screwdriver is pointing at where it should be. Why isn't it there?





And if you can zoom in on this one, Most of the bolts holding these brackets on were round Torx head, but there are 2 studs with nuts on them on the drivers side, one down low and one up on the head. Is that factory?




I'm mostly trying to figure out if these heads & block go together, same year or not. valve covers, heads, timing chain cover, oil pan all blue. Block is black. PO said it had been rebuilt, maybe just the top end.

Also, should this balancer be on further than this?

 

Pull a vc to see the head casting number. The intake has even been swapped from 89 . 89 didn't have a spot for a cold start timer switch. The balancer looks ok. The heads are 86 or older there was not a thick enough casting to run a stud for the serp setup.

 

GM went from blue to black in 1983. While it's possible someone intentionally painted the valve covers and heads blue, it's just as likely someone got some heads off an even worse smog donkey and tossed them on a short block.

The block casting number checks out as an 86-87 305, 1pc rear main, non-roller cam, blah blah. Interesting that the heads appear to have the Torx studs, spreader bars, and nuts from a 85-86 TPI car, but not the TPI valve covers.

I'd check the head casting numbers, and if they're not anything special I'd sell the works ASAP and get something that's not cobbled together.

The studs and nuts on the serp setup are normal. GM used two or three studs, and the rest are the same torx bolts as they used on the intake base.

 

Here's a couple shots of the passenger side head. The engine has good compression and runs pretty good. If its healthy, I'm probably going to stick with it.
Will the missing bolt hole be an issue down the road holding the AC/air pump bracket?

 

I'm assuming the PO just used everything off the front of the original engine on this one. I thought everything would have been metric also....the nuts on those torx studs were 1/2". Found some other bolts along the way that were english also.

 

Heads are 416; typical early 80s 305. Used on LB9, LG4, and L69. Could possibly have come on a 86 motor.

What difference does it make whether they "came together" or not? That is, what decision are you trying to make, that would be altered by this "information"? Maybe there's some better way of making whatever determination you want to make, than ... that?

If it runs good enough to do what you want, use it. If not, turf it and get something else. None of the rest of that matters very much.

 

1/2" and 13mm are close enough to the same, most people couldn't tell the difference. SBC's from the 80's are a mix anyway because the threads in the block are all SAE and the accessories are all metric.

The missing boss in the head is no big deal. GMPP sells the Camaro style serpentine setup, and the instructions say if the boss isn't there on your engine, to just ignore it.

Looks like 416 heads. 305 heads. Not good, not bad. Somewhere down in "Meh.. Acres". Given everything, you've got some variety of mid-80's 305.

Everyone has to follow their heart on the 305 thing. For my money, I wouldn't put one back in a car if it's laying on the floor. But that's just me, 305 hater for life. There's that thing where a 305 will never be a 350. People will say "350?" and when you tell them it's a 305, they'll give you that "oh, that sucks" pity full reply, like you just found out a loved one has a terminal illness.

The best reason to go with something different, aside from more power, is technology. In 2017 I can't imagine rolling with a flat tappet cam, leaky valve covers, etc when a Vortec 350 crate is about $2000 with a roller cam, 1pc rms, centerbolt valve covers, and much improved heads. It'd be hard to justify not doubling the power and increasing reliability, etc.

 

Did some searching on this site, mortec.com
Found the date casting numbers on the block and heads and they are a day apart Jan '86. So that pretty much confirms it I think to be a complete 86 engine.
The TPI intake has the center holes hogged out and you can see the 2 bolts don't sit flush on the intake.

Thanks for the heads up guys.