I have a 1969 Corvette Convertible 4 speed with the L46 motor 350/350. What parts would need to be changed if i wanted to put a 427 or 454 motor in this car? The car also has the factory side exhaust.

Asked by Jan 21, 2014 at 04:57 PM about the 1969 Chevrolet Corvette Convertible

Question type: Maintenance & Repair

1 Answer


Your Corvette from the factory did not come equipped to handle the heavier 427/454. First what is needed is the large block suspension springs. I think the shocks will need replacing, also. The motor is larger so some of the steering stiff will need repositioning. The entire front suspension geometry will need to be replaced with larger parts. The radiator will need to be larger, the hood will not fit so a new one is needed, factory or after market is your choice. The larger engine will have complex exhaust clearance issues. The connection to the side exhausts may be larger for the big block. If it's power you want, I built my 350/350 up to have more HP that a stock crate big block, with faster revs, and no modifications needed although I did do it. Consider a 400 crank (stroker kit) cam, heads, larger or dual carburetors, or even an EFI. I put in electric fans, larger radiator, dual quads, Edelbrock high flow heads, bored out 0.040, new 5 speed, 2 1/4 stainless exhausts to Flowmax mufflers, and Hooker long headers. It is faster than the 69 427s, except the L-88, and has beaten the first reintroduced Z06 Corvettes with 405 rwh. Oh yes, I think the transmission will need to be changed out with the larger engine. Compare the costs. Mine is around 445 HP. $12 k on a new motor and all extra parts. The old one had three major cracks, got a bare block 4 bold main 350 and had it professionally built by a person that builds NASCAR motors.

2 of 2 people found this helpful.

Your Answer

Chevrolet Corvette Experts

  • #1
    John Carson
  • #2
    Vincent Parker
  • #3
View All

Related Models For Sale

Used Chevrolet Camaro
378 Great Deals out of 31,271 listings starting at $3,495
Used Ford Mustang
344 Great Deals out of 42,032 listings starting at $1,488
Used Dodge Challenger
171 Great Deals out of 25,855 listings starting at $7,250
Used Porsche 911
129 Great Deals out of 5,258 listings starting at $10,099
Used Dodge Charger
325 Great Deals out of 36,003 listings starting at $1,999

Used Cars For Sale

2018 Chevrolet Corvette For Sale
3 Great Deals out of 3,036 listings starting at $48,035
2017 Chevrolet Corvette For Sale
11 Great Deals out of 3,676 listings starting at $41,795
2016 Chevrolet Corvette For Sale
19 Great Deals out of 988 listings starting at $39,997
2015 Chevrolet Corvette For Sale
14 Great Deals out of 721 listings starting at $36,995
2014 Chevrolet Corvette For Sale
4 Great Deals out of 727 listings starting at $33,990

Content submitted by Users is not endorsed by CarGurus, does not express the opinions of CarGurus, and should not be considered reviewed, screened, or approved by CarGurus. Please refer to CarGurus Terms of Use.