An opportunity has presented itself in I have been offered a trade for running 455 with J heads for trade (I'm trading an old 4 wheeler which I never get to ride anymore). I currently have stock 350 installed in my 1971 cutlass with a 2bbl carb. My question is, without switching out heads, which engine is a better builder? just from what I have read the j heads are pretty much junk but it's not really in the finances to gets heads done right now.

 

Take the 455 with J heads. Build it for torque.

 

The 455 is better and you can always work on better heads later.

 

There is no replacement for displacement

 

My next question is what upgrades would you do first on the 455? I have been looking at a torker intake that is for sale locally and upgrading to a Holley carb

 

on that motor i would go with a performer intake.the stock 455 is a huge improvement over the 350,mostly change the intake for weight,use the q jet

 

Your original question was actually "swap a smogger 455-4bbl for a smogger 350-2bbl".
No brainer on that one.

I agree on the intake manifold and keeping the QJet.

 

Keep the factory 350 and perform the usual upgrades.

 

Seeing as how you are pulling the intake MAW (might as well) put it on a engine stand, pull the timing chain cover to replace the set. If the neoprene covered teeth are damaged (almost guaranteed) pull the oil pan. Clean oil pickup screen and replace oil pump shaft, your call on the oil pump. I've put Comps Cam (RV Torque cam, H268, I think, 0.456/0.456 lift) It woke up a similar low compression 455. I'd upgrade the valve springs, your call, nothing crazy I like 100 lbs seat pressure. Keep rpms under 5k. Dual plane Preformer intake. These engines will surprise you with the torque.

 

I built a 73 455 many years ago. I did a complete rebuild with a standard valve job on the J heads. I used L2323 .030 pistons with an Erson JB100 cam and that thing was a tire scorcher. 600' long posi burnouts from a dead punch with a 2.56 posi in a 1970 Cutlass.
I even ran a 13.89 @ 97 mph with that combo. Think of what it would have run with a good gear in the car.

 

The very first thing you need to do is to educate yourself in how to select engine parts that match for the application. The single plane Torker will probably hurt performance on that motor - it's designed for higher RPM horsepower and you have a small port, mild cam low RPM motor. A dual plane performer would be a better choice, as would a properly calibrated Qjet. Free flowing exhaust will help, and be sure the distributor timing is optimized for the application.

 

Thanks for the answers! As you can tell, I'm really new to this and I am willing to learn

 

I really like the 350, it is a more durable motor, especially pushing higher rpms. Many have bottom end issues with the 455, when pushed in the rpm department. That said, both have huge dish pistons giving dismal 8 to 1 compression. The 350 is giving up 105 ci and has a 2bbl, use the 455 even as is. Get the Performer intake to save weight, use the original Qjet, small cam upgrade, new timing set and all gaskets. Then buy Cutlassefi's 414ci stroker kit for your 350, since you will have it sitting there and have an awesome performer.