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it's amazing what you guys can determine with limited information..... ..
OP greg
I didn't "determine" much at all ... I guessed.
??? So ... again ... what is location of the business on the work order/invoice shown in post # 1 ... guessing it is a WO ??? ... ... OTOH, maybe it's only a summary of work-parts purported by a seller ?
The modification was done 15 years ago .....I own the car now ....the guy I bought it from put 15000 miles on the work that was done .....he owned the car for 2 years I don't know what happened before he owned it
also when I turn on the air conditioner I can feel cold air down by my feet but nothing comes through the vents don't know what's going on there
The HVAC system is vacuum powered, with the default position being heat (floor vents). Consequence of being designed in Detroit I guess. Do some searching on the forum for this problem. Very common for these old nylon hoses to crack and break with age.
While you are in there, rebuild the valve which directs the vacuum. If the lines are fine, this is most likely the problem. The valve works by rotating two discs that have a maze of pathways on them. As you move the selector arm, it rotates the assembly, directing vacuum through the maze to the appropriate output hose. The two discs have a layer of high viscosity silicone grease between them. This dries out over time, and according to many folks on the forum replacements come with very little of this grease and often leak right out of the box. Better to rebuild yourself.
The modifications were done by keech's Performance Machine out of Sarasota Florida ....from what I've been able to research this guy does high performance rebuilds and seems to have a solid reputation building sweet engines with Corvettes as a specialty
Too many compression ratio-related variables to Know ... actual compression ratio is major determinant of resulting power.
Seems motor was rebuilt & bored thirty-over ... they replaced pistons but who knows if flat or dish or dome ...
... their respective volumes are quite different ... piston volume is major determinant of compression ratio
Head gaskets available in a wide range of volumes ...
... gasket volume is major determinant of compression ratio.
Seems motor was rebuilt and OE cylinder heads were replaced with Edelbrock Performer RPM heads ...
... those heads available with at least two different combustion chamber Volumes ...
... combustion chamber volume is a major determinant of compression ratio.
We don't know which piston volume nor which gasket volume nor which chamber volume so we cannot estimate compression ratio.
But I'll make a WAG ... a Guess ... they installed the more common/conventional rebuilder parts.
> Sealed Power Flat Top piston pn H345-30 has compression height 1.548" and volume 6.9 cc.
> Most Common composition head gaskets are about 0.039" thick & have volume about 9 cc.
> Most Common aftermarket cylinder head chamber volume is 64 cc.
I GUESS this 355 compression ratio is about 9.3:1
With about 9.3:1 CR, crane 100052 216*/216* .454/.454 cam, decent edelbrock heads and headers ...
... My WAG is ... I GUESS it'll make about 320 - 330 hp on engine dyno on pump gas.
This has a Flat Tappet cam ... if motor was assembled by competent builder ... and it was broken-in properly ... this motor should be very reliable.
The combo listed on your receipt should be a fun and reliable street motor -- are you going to beat 6/7/8th gens light-light, NO but it should be respectible
Should be a sweet running street engine. You got a good deal on a solid car with a solid engine. Couple recommendations:
You need to figure out if it will run on 87 or if it needs 93 octane not to ping.
Make sure you buy zinc additives for your oil or buy old fashioned oil with zinc (like Brad Penn) if you want that flat tappet cam to live long. If you do, it will, as long as prior owners did.
Please buy a larger air cleaner like a corvette 14 inch drop base chrome top one, I feel that small one is strangling your engine. May be worth 10-20 hp.
Valve covers? Mostly looks, but I'd prefer closer to stock, it's no race motor. L82 ribbed ones would look great.
Check your PCV valve and make sure it is in one valve cover and the other one has a breather. With a working PCV system your engine will run cleaner inside and you'll be happier. Personally I'd drop the the race "breather' on your left valve cover. The AC air cleaner has a hidden breather inside the air cleaner and it will look cleaner under the hood.
Last edited by leigh1322; Nov 4, 2019 at 07:19 PM.
Here's one example from Paragon. You have many options, diff level chrome on cover, etc. LT-1s had the vent pipe come out at a diff angle, most others were the same, SBC & BBC, Roch & Holley carbs.
Last edited by leigh1322; Nov 5, 2019 at 05:36 PM.
