Here is my question, will a stock 4.3 flywheel fit inside Archies adapter plate? The reason I ask is I'm planing on doing a 4.3 swap, I'm not happy with my V8 swap, and I planned on autocrossing so a 300 hp 4.3 is a way better option. My current fly wheel is for the older two piece rear seals. So I know it won't work, but i was thinking if the stock fly fits in side the adapter plate then its a matter of setting up the flywheel on a mill and a rotory table and drill and tap the new bolt pattern.

Any Halp would be cool, and any info from other 4.3 swaps would be great too.

Ok I measured my 4.3 flex plate and it made me realize my own answer, how ever I came accross some other material that suggested using a 153 tooth flywheel from a cammaro and putting your bolt pattern in for the clutch pressure plate.

My 4.3 flex plate measured 14 inches
My adapter plate 13 inches little problem?
What other flywheels would bolt up any 153 tooth chevy flywheel or certain years and engines??????

Sell your old flywheel and purchase the one piece design from Archie and have it balanced to the 4.3L, that will probably be the safest and most accurate approach to go with his kit. However if you insist provided the weight on the 4.3L flexplate is far enough inboard you can remove the ring gear by grinding away the welds, take the plate to a machine shop and have them turn the plate diameter down and remove a ring gear from a fiero manual flywheel and weld it in position. I did it with an SBC flywheel but decided to go with a manual transmission instead. Why were you not happy with the V8 swop?

[This message has been edited by Joseph Upson (edited 12-30-2005).]

I found it not as clean as I would have Liked it. Its just a matter of taste, I found the 4.3 stock puts out nice numbers and its easy to rebuild and put power in it, I can run a normal belt system no worries about electric pump problems, I guess my plan is to use the most off the shelf stuff as possible, reliabilty and ease to change things, the 4.3 I'm building up should be in the 300 hp range and 100 pounds lighter, so I lose 40 hp from my current 350. The loss of wieght is important, I feel the 4.3 is a natural looking engine in there more room to change anything, more room to do sparkplugs and parts are cheaper and better, since they are all 350 stuff. IMO of coarse

I can't say anything bad about the 4.3 I own one in my Jimmy 222200 Kms on it and still running strong no oil leaks and doesn't burn oil. My 2.8 in my fiero Died at 210,000 kms, leaked burned oil and make some really bad sounds.