Product Description
A pair of MsPro Street cylinder heads, fully assembled with springs, valves, valve stem seals and valve locks.
Fits Small Block Mopar engines 318 cui, 340 cui and 360 cui as well as the corresponding stroker versions 390 cui, 408 cui and 412 cui.
These heads are suitable for stock to mildly modified street engines. For all-out race applications we can recommend other cylinder heads.
We have already built several Small Block stroker engines using these heads and achieved up to 550 DIN horsepower.
- All original accessories generally fit. One customer had to slightly modify his cast iron exhaust manifolds or the head because the manifolds contacted the head. Unfortunately we do not know whether these were the correct 340/360 manifolds for this port size or smaller 273/318 manifolds.
- Suitable spark plugs: Part No. E71
- Hardened valve seats allow the use of unleaded fuel without additives
- Heads are delivered fully assembled with valves, springs, retainers and locks
- Valve spring pressure suitable for hydraulic camshafts up to 0.520 in. valve lift
- Recommended head bolts: ARP-144-3601
- Valves are larger than on most factory heads and the area above the valve seat is also significantly larger than stock
- Valves feature smaller valve stems (11/32 in.), reducing valvetrain weight
- Rocker stands and valve height match new OEM heads. However, replacing heads may require different pushrod lengths
- Very high quality machining and finishing
- Finished with great attention to detail
- Extra thick in the head gasket area
- Very smooth casting surfaces indicating a dense, low-porosity casting
- All holes deburred
- All threads deburred
- Perfectly flat valve cover sealing surface
- Exhaust manifold threads are blind holes, eliminating the need to seal manifold bolts against water passages
- Heavy duty steel spring cups under the valve springs
- 10 kg weight reduction per head, resulting in about 20 kg less weight on the front axle
- Blocked heat crossover for cooler intake temperatures and increased power
Very good quality, in our opinion better than comparable heads such as Edelbrock, with similar power gains
With these modifications and some additional optimizations, around 50 hp more power can be expected depending on the project. For higher performance goals we recommend INDY cylinder heads.
Technical Specifications
Cylinder Head Material: Aluminum A356.2 T6
Combustion Chamber Volume: 65 cc
Intake Runner Volume: 171 cc
Exhaust Runner Volume: 77 cc
Intake Valve Diameter: 2.020 in.
Exhaust Valve Diameter: 1.600 in.
Valve Stem Diameter: 11/32 in.
Intake Valve Angle: 18°
Valve Guide Material: Manganese Bronze
Installed Valve Spring Height:1.715 in. with 0.060 in. Spring Cup
Valve Spring Pressures
170 lbs @ 1.715 in. Spring Height
210 lbs @ 1.600 in. Spring Height
245 lbs @ 1.500 in. Spring Height
280 lbs @ 1.400 in. Spring Height
320 lbs @ 1.300 in. Spring Height
345 lbs @ 1.200 in. Spring Height
