1969 88 Convertible

I recently purchased a complete 1969 Toronado engine with the intention of replacing my 1969 Delta 88 350 2bbl unit. The 350 runs healthy enough but I couldn't pass the opportunity to get the 455 as the owner lives 10 min from my home and has offered his help on my project. The 455 is on an engine stand in my garage and I plan on doing leakdown and compression testing.. ...the 455 will be a longer project, as I'm not sure if I want to keep it stock or not. In the meantime I'm thinking I could possibly upgrade the 350 with the following parts,
1. C heads from 455 (already has 2 in intake)
2. Holley 4165 mechanical double pumper from the 1965-70 era.
​​​​3. Edelbrock 7111 intake (would need to purchase).
4. Cam upgrade
5. Double roller timing chain
6. Oil pump upgrade.

Questions
1. Will original 455 valve length work on 350?
2. Would Toro intake work on 350? If possible I would add Holley Adapter p/n 1932 to accommodate Holley 4165.

My 69 Delta is driven as a country backroad cruiser with very limited city driving .
Appreciated any input.

olds 307 and 403

The C heads will drop compression a lot, don't bother on a 350. Good luck in currently finding a 7111 intake, Edelbrock intakes are in short supply new. The Toro BBO intake will not fit any 260 through 403. The 455 valves would fit with machine work, I believe they are slightly longer, need set up for the proper installed height if the stock valve train is retained, not cheap. A cam swap degreed with a quality chain would definitely help, along with a torque converter swap, something 2000+ stall. Even a stock iron 4 barrel and Qjet off another 350 would help. Good luck.

69CSHC

If the 455 is healthy and ready to go. I wouldn't bother doing anything to the 350. The 455 is an automatic 50% increase in power. It will feel like night and day. You would need a professional rebuild level buildup just to get the 350 to do what this 455 does in it's stride.

If you still want more power, much easier to generate it out of the 455. But being it's a pre 1971 Toro engine. It's already one of the best... I'm figuring going with a standard height intake will give you back some HP. Timing gear set replacement if not already done and enjoy.

But of course, like always you will have to pay to play. Premium gas is a must.

OLDSter Ralph

Don't forget the TH400 transmission

1969 88 Convertible

Appreciate the feedback. I am going to focus on the 455 engine swap. As was mentioned, I gain 50% more power, without any mods.