Stroker Olds or Cadi Swap?

[olds307 and 403]

Olds. Get the best heads you can: https://www.dragzine.com/tech-stori...erings-new-oldsmobile-aluminum-cylinder-head/

The good, they produce big numbers with the right work. The bad, the guy behind them is a thief and a liar. Kind of like the whole Bulldog fiasco. All typical for the Olds performance world. There are billet cores available that can flow big air, into the 400 cfm range if done up right. There is also Batten heads and the Rocket Racing heads as well.

 

[motorheadmike]

Woah - too much drama. Nevermind. Just put an LS in it.

 

[84dragcutlass]

Put the Caddy engine in it and sell the diesel to me

 

[lilbowtie]

May I ask how much your willing to spend ??

 

[olds307 and 403]

The budget is the big thing. What does it cost these days to cut the counter weights and rebalance a 425 crank? Too bad Olds didn't add more head bolts like their 4.3 V6 diesel. Stroking it in diesel form would basically turn it into a 6.2 or 6.5 without boost capability.

 

[Carson L W]

Honestly I'm gonna start looking for both the 425 crank and a 500 motor. Where I live the boneyards don't get picked over for that stuff and I could get lucky. I have connections to do the machine work, maybe not for the crank but for just about anything else. Custom pistons? Rods? no big deal. That'll save me money. I could deck heads and match ports, valve jobs etc too. If I did get the 500 I'd want to rebalance the crank on it as well, so that expense comes with either option. I don't have a set budget, just however much I can save up this summer building fences, maybe 3 grand this year? Just for the engine.

 

[fleming442]

If you find a 425, why not just drop that in and sell the diesel?

 

[Carson L W]

The dx block would hold up better I feel like if I raced it a lot. And sometimes you gotta do something just to say you did. If I found a decent BBO then I might, but either way I'd have to rebuild it.

 

[fleming442]

Just remember that 425s had funny lifter angles- requires a custom cam. The diesel block may also need the lifter bores bushed.

 

[iains]

What rods and pistons would I use with a 425 crank? and whats the difference between the 425 crank and the 455? If I did stroke the block I have, I'd want at least 400 cubes. what crank would get me closer to that ball park? Also, what to do about the gap left by the injector pump on the DX block? On the other hand I could pick a Cadi motor up for $300 bucks, then all the new parts, but I don't know how to get any more performance out of a 500. And then all the extra weight...

I have a mild 500 Cad. The engine is slightly heavier than a SBC, has a high nickel content, is very well made in terms of tight tolerances etc. The valvetrain needs to be swapped for parts that can tolerate more than 4800 rpm😜, the intake is complete rubbish, and if you have the budget, buy the aluminum heads from MTS.