[MidnightAuto]

So I figured it was about time for me to put up a thread that may be useful for others as I embark on a upgrade project. For context, I am a year or so into getting back into the hobby from 30 years ago. I finally have a garage to hold a car (albeit really small). The car going under the knife is a 64 A body convertible. PO took a crack at homage to the GTO from car and driver mag, but passed on before giving me all the details on what he had done. It is a 421 with a 66 tripower and 77 heads, cam was unknown till this morning (its a crower 60916) and 1.65 rockers with Petronix + MSD 6AL. forged dished pistons of an unknown CC, most likely .30 over. TKO 600 with 3.36 Yukon posi. Car runs strong, but never been to track to know baseline. I am looking to take performance up a notch but still be streetable and retain the tripower bling.

With the help of Jeff at KRE and some folks on this board, I landed on plan that has me swapping the 77 heads for KRE D ports with the 290 CFM port job. Cam will be a crower 60243, and I'll be re-using the 1.65 rockers. Intake will be gasket matched to a RAIV port, the largest the original tripower intake could take. I just got the motor broken down and you can see where I started from below.

So I will be updating this thread as I work through pulling this together to maybe help other novices like me. I am sure I will need some help along the way. Degreeing cam, checking for piston/valve clearance and checking pushrod length are all on the list of things coming.

[Formulas]

For some reason that eccentric looks a little to far off center

[MidnightAuto]

That might be the camera angle. That pic is prior to breaking motor down where it was running fine, no issues….

[Formulas]

Cool got a soft spot for 4.00 crank,
Be interesting to see how your combination turns out

[MidnightAuto]

I hear you. Something nostalgic about the 421...

[MidnightAuto]

Started working on the intake tonight. I can totally appreciate the skill of a good porter. I am clearly not. Wit that said, I can claim the holes will be bigger.

[steve25]

Even doing a gasket matching job is far more slow and difficult when you do not have a real grinder as is your case, but if you have the time to work that way then I guess it's all good!

[JSchmitz]

Looks good! Silver '64? Me too. How about posting a pic of the car? Good luck with your project.

[MidnightAuto]

cool. yep, silvermist grey. Here we are at the drive inn....

[MidnightAuto]

Intake is done.

Because po left me flying blind on upgrades- Jeff and I looked at a pic of my pistons from snake camera (coupled with the fact that my car has never pinged once with the factory 77 heads that are 10.75 to 1 on a 421) and decided to leave the new kre heads as cast - 65 cc. Well I wanted to confirm bore/stroke tonight and got some unusual measurements. Which I measured twice. Bore is 4.2. And stroke is 4.25. That would make this like a 470ish ci. Which seems wrong as that would have to be more than .60 over on a 421. I think.

Anything special I could be doing wrong on measuring?

For those wondering, I did just measure the cc on that dish below. 33cc. Yowsers.

[MidnightAuto]

And bonus points if anyone can identify the piston brand based on that dish shape. I have no idea.

[John Milner]

Someone could have slipped a 455 crankshaft in it when it was rebuilt. A 33 cc dish with the 455 stroke would have likely put the compression near 9.5:1.

[MidnightAuto]

That would be pretty sweet if it is a 455 crank. I’m just baffled by that bore. 421 is 4.093. I got 4.2. Seems like I must be doing something wrong on that. I’m going to measure again tomorrow.

[steve25]

Is that a 421 block!
The bores have valve notches for the mid 67 and up heads.
Judging by the almost milled away original valve notches those pistions look like they started life as 67 and up pistions also.

[MidnightAuto]

Think I figured this out. First, it is a 421 block - 35B big car, only 2 freeze plugs per side. Late 1963 date code.

The calipers I am using are digital/analog. Had a bad battery so was using analog- seems the pointer is confusing me. So I bought a battery to get digital read- that is showing 4.15- which aligns with being .60 over. So I guess I am chalking this up to a pleasant surprise- 461 ci.

Makes me wonder if I should take the cam up one level- but I also don’t want to be greedy. Let’s see. Will think on it over weekend.

[MidnightAuto]

Was excited to start putting cam in, and realized there is no cam key with the cam from crower. And I dropped my old cam off with ups today for Milner- with the cam key in it. Sigh. Well I hope Napa has these things in stock, so I don’t blow the weekend progress.

On an unrelated note, the lobes on the new cam were very dark- not shiny metal at all. I assume that is normal? I have some break in lube on it now, slightly more shiny but was just odd to see them very dark gray…

[steve25]

The Cam lobes may then be Parkerized I would assume.

[MidnightAuto]

Had to look that word up. I’ll ask Jeff where I got the cam from.

On an unrelated note- I’d love some help with taking a shot at identifying my rods. Are these stock or something else? Pictures are not great, but best I could do with snake camera. Note the rods have numbers stamped in- and does not look to be previous cylinder hole. I can make out a 3075 on that one rod. Perhaps that is weight. Anyway, what is your take on these rods?

[Formulas]

Not stock rods at all, wild arse guess RPM brand or similar not top shelf but fully capable for strong street duties. Either 5150 or 4340 forged either of which are a better than stock rod

[steve25]

There a aftermarket forged rod, what brand I can tell without a face on picture with them out of the motor.

They are not a early factory forged rod because they do not have this straight cut above the bolt head pad as you see here in my first photo, and they are not a original 421 HO forged rod either as you can see here in my 2nd and 3rd photo.