Hi everyone. New to forum, but not to Vette's. Have a beautiful 66 that I've owned for several years now. Non original engine car but very original in all other respects and very, very nice. Low mileage car, nassau blue, powerglide, came with 327 which was replaced at some point with a 1970 350 with less than 250 horses. Finally, I've decided to do something about that. The car is nice enough to deserve a good power plant, and that brings me to my question. I've found a 327 block, complete with heads and intake but I'm confused about the suffix code. It's a 3858174 cast with build code of F0131HCH. Date casting is of poor quality and I can't make it out. Looks like A21? but we can't make out last number, possibly a 5. My car was built in Sept. of 65 and came stock with power glide and, btw is a convertible. I know I'll spend around $5,000 on this motor and don't want to waste any of my hard earned cash on motor that couldn't have possibly been correct. I believe I've read that my car should have been either HT or maybe HR suffix code. This HCH code shows to be power glide car with 4B Holley, 300hp, and that's on the money for my car, but the suffix confuses me. I know some of you guys out there will know what it means and I could use the help. also, feel free to weigh in on whether I should be looking for correct 327 or should I go another direction. Thanks for any and all help and advice.

 

The suffix code for a 327 300 in 66 should be HO for just powerglide and HR for powerglide with AC.

Don

 

HO would be the non smog pump powerglide. HR is with smog. HT is a 4 speed.
If the suffix code is not HO or HR with a small block powerglide it really doesn't matter what it is as long as the casting and casting date codes are good. You could deck the pad and still have the same judging deduction.
I think I recall one of the NCRS guys saying something about 6 mos being acceptable for time spread between casting and build? If that is true then the A code block wouldn't be correct for your car. You would want a D-H to be safe. You'd have to be careful with an "I" not to overshoot the build date and "C" not to undershoot too far.
I hope one of the experts will correct me on the 6 mo thing if I'm off.

DT

 

HCH is a 66 327, 275 hp, powerglide trans, Holley carb engine installed in a pasenger car.

HCR would be the same engine with a Rochester carb.

1966 seems to be the only year that Chevrolet added the third character to represent the carb type, and only for this engine application.

 

What is your goal for this car? If you aren't planning to take it to NCRS, then I wouldn't spend extra money to get an engine with the right date codes and usage codes - because no engine will be the original engine for your car anyway. At best you'll find an engine with the wrong VIN on it and will lose points at an NCRS event because of it.

If you want something that looks right, then a 327 with the hole in the back of the block for the PCV system is what you need to focus on.

 

That's the right casting number, but the casting date won't work for your car (assuming you plan on having it judged); the block casting date should be 2-6 weeks prior to the car's final assembly date to be "typical", but NCRS allows up to six months for full credit.

If judging isn't in your plan, that's a good block to work with, as it's correctly configured with the casting number for a '66 and has the crankcase vent hole at the back.

 

Thanks for so much good input everyone. I have no intention of showing this car or having it judged, just wanting to have a better driving car, more fun to drive. At the current 200hp, it just doesn't make my heart beat fast, you know. It's one of the nicest condition classics I've ever owned. Sold at auction a few years ago to PO as having 42k original miles. Car is clean enough to make me think that might be true. The 327 I've found locally can be bought for $400 but, as someone pointed out, the date code isn't quite right, a little too far out. So should I find a date coded 327 within my car's range, buy the one locally for $400 and rebuild it or buy a crate motor and not worry about originality at all?

 

No point in that given your stated intentions.

Not a bad option

Another good option, but be aware that a crate motor likely won't have the PCV hole in the back of the block, so you'll have to find some other way to vent the engine. If your goal is that it should LOOK correct even if the dates aren't right, then a typical crate motor won't do that for you.

 

I've been struggling with the same basic questions with my 61.
In the past year I've bounced back and forth between rebuild, crate, big cube small block, and period correct.
I'm a little "luckier" I guess since I have higher performance components in my existing 350 to work with, which factored greatly in my decision to rebuild what I have and to slowly assemble a "correct" 283.
But if I knew of a complete 61 "519" engine locally, I'd be on it like white on rice!
In your case, $400 for a complete correct casting 327 is almost impossible to walk away from. I don't think the slightly early date will matter a bit in terms of resale value.

DT