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uk dart

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Hi boys, I have a 360 engine with heads, the block is stamped 3418496 7. 360, and date coded 8.12. 71. heads are 3418915 f, and 3418915 g. part no on piston skirt is 3418919. im wanting to know some spec on these parts, am I right in thinking these are high performance closed chamber heads,same as the 340. also what would the comp ratio be, im assuming with the part no that the pistons are stock. lastly I cant think what this engine would have been fitted to from the factory, I thought the highest performance small block from that year would be a 340. any help greatly appreciated. Richard. ps cast crank part no 3418640.
 
Sounds as though you have a stock 360 engine. Those heads were used on multiple year 360's, I have a 77 engine with the same heads.
 
They came from the factory on '70-'72 340 and '72 360's..
 
You have one of the early blocks. It has thicker cylinder walls - Keep it!!!

The 71's had the highest compression from the factory, but yours is from a 72 model year engine. I'm not sure if that still had the higher compression pistons from the factory, but I would look into it before getting rid of the stock pistons - they're a good find if true.

Your heads should end in -915 for the casting numbers. For those years, they should have 1.88" intake valves, but you can open them up to 2.02" very easily. They are good heads.

Put a good double roller timing chain, cam, and intake and carb on it, and it will run well....
 
some spec on these parts, am I right in thinking these are high performance closed chamber heads,
Click to expand...
open chambered. Google em as there is some VG info posted out there that will help quide you
 
No 340 ever came from the factory with closed chambered heads and yours aren't closed chambers either. They are virtually the same head the 340 used except with smaller intake valves. The compression ratio is in the neighborhood of 8 to 1, 8.5 to 1 max. 360's were first used in trucks in the early yrs then they started using them in cars in 72 or 73. They were not considered a high performance engine until about 74 when they started putting a 4 barrel carb on them. Even though they had smaller valves and low compression I've seen some of the early 4 barrel models run fairly strong.
 
thanks for replying fellas, so which cars came with 360 engines as standard in 71, 72, 73. and would my 71 date coded block have come with these heads from new. the block date no reads 8.12.71, does that mean 8th dec 1971, or 12th aug 1971. ive googled the heads and your right they are open chamber, and have 1.88 and 1.60 valves, but you say they can be opened upto 2.02 (what do you actually mean). the motor has a double roller chain which I want to renew,what make would you sujjest. it also has an edelbrock performer rpm intake and looks to have an aftermarket cam, I will get some nos of it to try and identify it. it also looks like it has some larger dia pushrods , do we know what the standard dia is. so are we sure the comp ratio would only be in the region of 8 to 8.5 to 1 with these stock flat top pistons. very greatful for your replys. Richard.
 
uk dart said:
and have 1.88 and 1.60 valves, but you say they can be opened up to 2.02 (what do you actually mean).
Click to expand...

It means that 2.02 intake valves can be installed to replace the 1.88's, in other words there is enough room to do it.
 
as I already mentioned in my prior post 360's were not used in 71 cars, only trucks. When they did use them in cars starting in 72 it was large cars such as Plymouth Fury's, Dodge Monaco's etc. Then in 73 or 74 they started using them in Cuda's and Challengers, Dart sports and possibly Dusters. It really doesn't matter though because they were all identical engines. The only exception is the few they installed a 4 barrel carb on.

And yes I'm positive the compression was that low even on your early engine. The factory ratings were way over rated. If you measure the compression of just about any Mopar engine made you'll find it's 1/2 to 3/4 point lower than what the book says it is.

915 heads are stock for your early 360.

Larger pushrods means nothing other than they will possibly last longer.

I'm not positive about the block date but I believe it means Aug 12, 1971. Really don't matter though cause it's considered a 72 engine no matter which code it works out too. Engines built that late in the year wouldn't get used for a couple of months and by that time the 72 models would be on the lots
 
I have 2 1972 360s. One is a January 72 and has flat top pistons the second is a April 72 and has dish. Both same block casting as yours. Flat tip 360 pistons I think 8.8 compression vs 8.5 for later years...
 
I would bet that the OEM dish pistons are in a passenger car engine and the flattops are in a truck engine. I've never seen OEM flattops in a car engine, just dished. The casting dates can be used in subsequent years.
 
this is a great site, your all very helpful,at least I know what im working with now, although does anybody know how to identify camshafts, the nos on the end face read 5440, 2117, then some very faint nos that maybe something like 7777, and theres some red paint on the shaft then the nos 1136,. this engine had an edelbrock performer rpm intake, ive been on their website and they list a cam and inlet package and the cam no is by7177, was wondering if this could be the same. Richard.mopar fan, 68 roadrunner, 68 satellite, 72 dart all in the uk.:burnout:
 
Pretty hard to know about the cam, unless you know for certain brand name. Some companies can tell you, like Crane for instance, they keep a data base of all of their grinds.

You can use a couple of V blocks and figure out what the lift is with a dial indicator, duration will still be a mystery though.
 
uk dart said:
this is a great site, your all very helpful,at least I know what im working with now, although does anybody know how to identify camshafts, the nos on the end face read 5440, 2117, then some very faint nos that maybe something like 7777, and theres some red paint on the shaft then the nos 1136,. this engine had an edelbrock performer rpm intake, ive been on their website and they list a cam and inlet package and the cam no is by7177, was wondering if this could be the same. Richard.mopar fan, 68 roadrunner, 68 satellite, 72 dart all in the uk.:burnout:
Click to expand...

It could be a crane 7177, but it's hard to tell.

The best way is to degree the camshaft to see what it is...
 
ProStocker273 said:
I have 2 1972 360s. One is a January 72 and has flat top pistons the second is a April 72 and has dish. Both same block casting as yours. Flat tip 360 pistons I think 8.8 compression vs 8.5 for later years...
Click to expand...
That's pretty interesting. I have a June '72 that was a '73 model year motor from a C body, it had 587s stock. I wanted to think they were flat tops but they may've been dished- everything I've seen says they should've been. Everything I've seen indicated the flat tops as early production '72/'71 pistons only.

360s came out for the '71 year in trucks, vans, and C bodies. I believe there may have been other cars added for '72 and '73, but for '71 it was only C bodies, trucks, and vans. They all had 2 barrels and came with 915 heads with 1.88 valves. '72 340s had 1.88 valves too, '73 340s and 360s got 587 heads.

fishy68 said:
I'm not positive about the block date but I believe it means Aug 12, 1971. Really don't matter though cause it's considered a 72 engine no matter which code it works out too. Engines built that late in the year wouldn't get used for a couple of months and by that time the 72 models would be on the lots
Click to expand...
Most of my original engine stuff had a couple weeks to a month between the engine cast and production date of the vehicle. I know they can be longer though.
 
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