Engine on type 65 coupe

[mtifft25]

I am about to purchase a factory 5 type 65 coupe and was wondering which engine to go with price performance and fit wise a 302 or a 351w thank you

[wallace18]

Both will work well, here is a pic of my 5.0 in mine.

46539

[Gordon Levy]

I've done many of both, Depends on what you want performance wise and what induction system you want to run.

[tirod]

Pros and cons of them: The factory cast 5.0 block is lightweight - and suffers some strength at the higher level outputs. Since the kit is already tail heavy a light block in and of itself isn't a "better" thing. It can be stroked up to about the 340 cubic inch level but that's the limit. The kit is inherently designed for it and has been since the 289 used in 1963. Plenty of power from it as they raced in the 350+ hp level and it was a good combination.

The 351 weighs more - not a disadvantage as it puts more iron in the cam gallery where the 5.0 is weak. It's also the factory "stroker" done right with another inch more deck height, and it also moves the cam up further in the block leaving a lot more room for a stroker crank. This is why it's relatively easy to get 427 inches from it with no more grinding that it takes to fit a stroker into a 383 Chevy - it's practical limit. That inch of extra height also uses longer rods which are theoretically better. The block as a whole is not only 50 cubic inches bigger but will deliver 50 more hp at street trim outputs and tolerate up to 700 hp in more extreme forms -given some careful building and parts selections.

The disadvantage is the higher deck height - you lose an inch of intake height in the kit - which was never designed to take tall ram manifolds or drag race induction systems anyway. They didn't exist in the 1960's and weren't used for road racing. Webers on a short runner intake were the focus, and all around powerband tuning was dominant. It needed to keep some horsepower at lower rpms simply to pull out of corners and accelerate, which was much more frequent on a road course than top end acceleration.

The kit - including the headers and other parts that come with it - is set up for the shorter deck height. Therefore the additional costs of going 351 include newer headers, etc. But upping horsepower always has follow on consequences that trickle down through the drivetrain regardless. You can't get something for nothing.

In a mid range power build I will speculate you can spend the same money and the 351 will deliver the extra 50 hp without additional cost - and it won't stress the engine block nearly as much. In terms of longevity it's a valuable tradeoff compared to the peaky hp curve of a stroker 5.0. On the other hand, the car doesn't need more hp - it's already in the supercar class with it's power to weight ratio and top tier performance. It might lose a youtube video racing Vipers or such, but that's the rarefied atmosphere where it plays - not dragging main in stoplight competition against Civics.

One isn't inherently "better" than another and it's certainly not a moral value judgment. It should also be apparent which I prefer, but 351's are a minority in builds. It's the Pro Touring and street machine crowd who keeps expanding their use today as it delivers economical, rugged hp at the higher end of the small block range. Moving up to the next level is expensive - and it consumes budget for other items.

There are other mods which have incremental value but a lot of addon work - reversing the motor mounts to push the engine forward, full power and air, IRS, and non donor brakes. The engine gets a lot of attention but for the most part other than looking under the hood you have to look at a time slip on the track to rate it with it's peers. Goes to - what is the purpose of the car, and where will you drive it? Show? Street and club? Track? Each has it's distinct demands, and it takes some thought to define what you really want before you launch into an engine specification that winds up being at cross purposes to how it will be used.

How fast do you need it, and where is it going? So follows which engine.

[mtifft25]

Thank you! I think we will go with the 351 found one for a great price with efi.

[CraigS]

You won't regret it.

[Garry Bopp]

I had a 351 in my coupe ... had to use a low rise intake (Edelbrock Performer, dual plane) and small air cleaner for hood clearance ... ended up with less than 1/2". You may have clearance issues, depending on what type of EFI you plan on using.

Garry