Motor Year Choices

[tah]

I'm just getting my 72 to the point of pulling the driveline. Not sure which route I want to go right now, n/a or turbo, but I need some advice.

 

#1. Let's say I want to go n/a and get a 280 motor with the 5 speed. Any years I particularly want over any other years? I'd plan to use my original SU's if I go this route.

 

#2. If I go with the 280 motor, what internals would you have done (don't plan to go CRAZY but a fresh rebuild would be part of the budget) and what kind of power increases would you expect?

 

#3. If I keep it real simple and "massage" the 240 block, what would you do and how much power would be expected?

 

#4. Now then the turbo route. I remember reading that the 83 driveline was the most desireable, but don't know why. Please explain why I'd want the 83 over say the 81 or 82.

[roger.svoboda]

Well the 81 only came in automagic tranny. Got a beefier driveshaft and a R200 rear end and cv joint rear axles. 82, 83 came with Borg Warner T-5 tranny R200 rear end and cv joint rear axles bigger clutch. Clutch is the same diameter as the 2+2

[Phantom]

Plus, in NA form, the 82/83 have a head design that delivers about the same HP as the earlier L28's but move the max torque down to 3,000 RPM from about 4,500. Significant improvement in throttle response. Also the 81-83 5-spds have the best gearing to mate with the 3.90:1 R200 for overall daily driving performance. Other options might be better if you are planning a car that is primarily for the track.

Sounds like you have some more thinking and searching to do.

Since you have an L24 you could get yourself a Diesel crank (L28D), use the L24 connecting rods, and build yourself a stroker. Put in a better cam, better intake, headers & exhaust and call it good for a while.

[racerx260]

The 82 83 turbo ecu is easier to convert to a 240. Wiring is simpler. 81 turbo has the best stock cam.To get the best n/a 280 motor you really have to mix parts. If you use an 81/82/83 flat top piston motor with the p90 head you get the best compression and head design and the square ports.the p79 head that comes on the 81/82/83 motor has the same head design as the p90 but has liners in the exhaust port.The 260 cam has the best duration that best suits the carbs you want to use.I had a motor with the f54 block p90 head 260 cam 260 intake and 240 round top carbs and it was a great combo with good tourqe.The compression is 8.8 and can use pump gas as this is stock.If you use an n42 head it has square ports but compression will go way up and is more prone to knock.Use the engine calculator on this sight some were to get exact compression.If you dont want to mix and match just get an 81/82/83 flattop motor and put your manifolds on it.You'll like the extra tourque.I now have a 83 turbo in mine but have rebuilt it to have 8.5 cr . I missed the lowend of the n/a motor.Now I have tourque and it revs out like a cut monkey.good luck